@sei shin It probably averages 0.5-2 hours per minute of video. I've spent 10-20 hours learning about screen printing in this case, for example. This is another reason why I like the format of 10-20 minute videos in general -- it's information concentrate!
I spent most of my life in our family run screen printing business. We did huge volumes (like, millions of prints a month on 6 12 color automated presses), and obviously had to invent techniques and learn a lot of stuff by trial and error. My job during my high school years was to make screens. That meant stretching them, coating them, shooting them, and cleaning them. I probably saw that life cycle of a screen 1000 times. Right away I have to say - you weren't using the screen coating tool properly. You need to fill it with a bit less emulsion, then while the emulsion is till deep within the coater, you tilt the screen enough to be able to push the coater up to it so that you can tilt the coater to the point where the edges are pushed into the screen. Then you tilt the screen and coater together until the emulsion is just touching the screen, and lift up. As you near the top edge of the screen, you tilt back to the starting angle, rolling the edge of the coater back so you can feather out the edge of the emulsion to avoid making a bead. Do the same for the other side, and you end up with thin layers on both sides with no beads. Aside from that , you've done a great job at describing the process for people who have never heard it. That said, some other things to consider: Coating the screens properly makes for screens that produce higher resolution prints and last a lot longer than using the more expensive emulsion sheets. They last longer because the mesh is fully captured by the emulsion layers on both sides of the screen. Those layers are also thinner than the emulsion sheets, which means you get more crisp stencils. The light you use to expose the screen is prone to creating shadows that spread (especially if the light comes from a single point). The thicker your stencil, the more your shadows spread, producing a more "blown out" print than a thinner stencil. You also want as little amount of gap between the screen and the substrate you want to print on as possible. You need some, but the larger the gap, the more than print will be distorted. It's not a big issue on single color prints, but if you're doing multiple colors and need them to have tight registration, too much stretch is a nightmare. 300 micron is great, but you can get as small as 50 micron with the right combo of mesh, emulsion, ink, and process. Back in the day, we used to do 4 color process printed on fabric that looked as good as a modern CMYK printed magazine image. It wasn't easy, but it's totally possible.
Thank you for your informative post. Could you recommend a mesh count, emulsion and ink for very fine line drawings. I have tried with 300 mesh but not getting the fine line/detailed high resolution results I need. I am not sure if its my printer, the emulsion, or the ink I am using.
@@schediastriamoda7459 Curious if you found a solution. Curious what you are trying to reproduce. A 300 mesh with 1 thing coat each side, is capable of very high resolution. Art file, film out put, screen 'burning' (exposing) print technique, all factor into the final print quality. My impression is most 'amateurs' (no offence intended) just don't have all the parameters together at once. 300 DPI file printed Black, and I mean BLACK on CLEAR film tightly sandwiched with properly coated screen and exposed with a proper light source. NOT a grow bulb (fluorescent), NOT a work light. The exception to the grow bulbs is IF they are metal halide, then OK. I use a home built exposure table with a 1000w metal halide and it burns a very good screen. I print tshirts for a living and happy to help anyway I can. Tell us more about what you are trying to print, and more about what 'stuff' you have..screens, film output, exposure etc Cheers
This and @Joe Shmoe 's comments are fantastic! Thank you both so much :). As a photographer with darkroom experience, this cleared up much of my doubts which remained after the main video :) . Please consider doing your own videos on the topic; I'd love to see them.
I dove into the comments to see if anyone talked about point light sources (like the sun) vs diffused light sources (such as the UV table in this video). Point light sources are definitely more appropriate for fine detail as diffused light sources inherently reduce shadow sharpness.
Having grown up in the printing (textiles and paper) industry, this takes me back a way. In a hurry we would be able to get screens dry after coating within 15 minutes or so using a hot room heater, we had a yellow light room with screen racks to hold 50 screens at a time while drying. When exposing screens, we built a vacuum frame, glass front with rubber backing, the artwork would be placed on the screen in register across a number of (ink) colours then placed in the vacuum frame 4 screens at a time, glass closed and latched and vacuum turned on. The vacuum means that all air gaps are taken out and the artwork is tight against the screen. Our light source was a carbon arc lamp, with 3/4” carbon electrodes sat about 4 feet away from the vacuum frame. Hope this is helpful to someone :-)
We also built our own screen stretching machine, which was able to tension up 4 screens at a time :-) it used 24 pneumatic cylinders and overcentre clamps to bite on to the mesh. We would usually have a dead zone 20mm to the left and right, our off-contact approx 2-3mm being aware that any extra stretch can distort the artwork out of scale, especially if it’s non-linear stretch, more in X than Y
@@JBFromOZ I used to work in the printing industry when it was all still about film in the 80s and early 90s. I used to expose printing plates with a NuArc carbon arc plate burner. Don't breathe the fumes! :) We later went to a pulsed Xenon burner.
@@HackaweekTV I still run an old heidelberg GTO built in the late 60's - we still have the xenon plate burner set up for use with the old negatives. Our new plates are actually inkjet printed onto metal plates with an Epson wide format printer; it's not as durable as the UV plates, but the whole assembly fits in the same footprint that the film processor alone took up.
Years ago when we were still using a carbon arc light to expose the screens, we would turn the arc on for just a second and turn it off so that we could light our cigarettes on the end of the glowing hot carbon electrodes. Good times.
Just a couple of tips: You can use standard cartridge paper for exposing a screen, a light coating of vegetable oil will make make the paper translucent, once you wipe all excess oil away this works brilliantly. To get dark blacks on a printer use the CMYK values 60 40 40 100, this is known as 'rich black' among printers and will get you the most contrast in your prints. Great video!
"This passes more UV light than the clear plastic does. I've measured it." Of course you have! I've come to expect no less from you - I've only recently discovered your channel but I'm continually amazed by the breadth and depth of your knowledge, experience and the lengths you go to really understand things. Brilliant.
This video is absolutely the kind of resource that the internet needed for high-res printing on substrates which aren't t-shirts. I wish you'd put this video together about a year ago! We went through a lot of experimentation in terms of applying emulsion, exposure times, screen setup, etc and came to many of the same conclusions that you outlined in this video. Even after all that I still feel like I've learned a lot from the depth and accuracy of the information you provide in this video! We'll definitely be giving the emulsion-film a shot next time we have a batch of screens to make. I feel like it will greatly increase the success and resolution of the screens we make to print on our guitar pedals.
I looked all over the Internet about 4 years ago looking for info on making high res screens for small electronics panels and finally gave up. You have pulled it all together and given me enough info to at least get started and make a stab at it. Thanks so much Ben for your excellent info which was explained very well. You remain my favorite Professor !!
I've watched a million videos on UA-cam about the silkscreening process, and this one is by far full of the most useful and valuable information. The narrator wastes no words. Tons of knowledge gems in here. Thank you!
For about 15 years I've been using Pictorico OHP transparency film and inkjet printer for making my screen transfer positives. The sheets have an emulsion on one side that holds a high saturation of ink, so you can make a very dense image.
Fully agree. I've been using "Bab's" Transparency film for a few years, I'm pretty sure it's rebranded Pict film or very similar. It really does make the densest saturations I've ever seen. The vellum prints he made looked just like the ones I struggled with for a while before I found Bab's. My exposure times went down 3-fold as well.
I never thought about having to leave a gap between the screen and the part you're printing on. This way they only touch for a second when your pushing the squeegee then separate again. I'm sure you've helped a lot of people with this well thought out video. Synth nerds (and people who make DIY test equipment) are always looking for ways of making better looking front panels.
I wish I had this video about eight years ago when I took three college classes on screen printing. So much more concise so much more to the point I’m actually going to go out and buy a couple screens right now because I feel like you did such a good job on that video. Thank you
I plan to screen print the markings on the instrument panel of my homebuilt airplane. Like you said, all the info out there is for t shirts. This video is EXACTLY what I was looking for. Very detailed. Couldn't ask for a better tutorial. Thank you so much!!
This is a really informational video and I thank you a lot for it. Since I was making my own PCB's not so long ago, I can give all of you a little hint. When you print your design on a "paus" paper, as mentioned in the video, you can increase the contrast dramatically by laying the design flat with toner facing up. All you need is a shoe box cover and some pure acetone. Drip some droplets of acetone on the inner side of the cover and then place it over the design for a couple of minutes. The difference will really be obvious, if not dramatic.
Yes, I know ElM, when I was a young fellow I silkscreened wrestling poster as a part time job until the fumes had me riding my bicycle home along building walls but back the next day - and I'm still interested in the process. And my father spent much time perfecting his own ability making PCBs for short run production. I kept way from photography until digital came around as proficiency then didn't require the chemistry degree. And of course technique in small run is greatly different from production and mass market requirements - each branch spawning its own complexity of knowledge. The video and comments here show this wonderfully (and on this channel generally)..
We have some kind of set up like this at work. I am an aircraft mechanic and sometimes we have to etch our tools with our name or initials. We start by printing initials out on a transparency and then we lay this on top of a blue gel sheet (It seems to be a fine mesh sandwiched in between two sides of this emulsion stuff). We put that under a UV light for two minutes, (with the print out on top) to expose. We scrub the unreacted portion off with a sponge and what appears to be just water. Now you have a similar thing. However, we use this to electrochemically etch our tools. The etching device seems to be a one to one transformer that plugs right into the wall. The secondary coil is hooked up to an alligator clip and one side is hooked up to this apparatus that holds a felt pad with a metal screen under it. YouCan put on different types of chemical in order to etch into different types of metal. You can also put a diode in series with the alligator clip to change it from AC to DC. This has the ability to make a black oxide rather than etch into the metal. Anyway, you apply at the alligator clip to a part of the tool or a sheet of metal where you lay the tool on. You lay your pattern down on the tool and press the chemically-wet etching pad on the film. In 10 seconds or 30 seconds it makes a pretty decent mark. It makes really nice metal etchings. It’s better than taking a vibropeen etcher to it... it just takes longer. This set up is a kit that we got but I can’t remember the name. Also, how durable are the emulsion patterns after you make them? I hear about a useful life of certain patterns that people make before they have to make another pattern (like scraping the squeegee over it a bunch of times will wear it out or something)
Great informative video. And just as a couple of other people who left the comments, I have also spent probably half of my life working in my screen printing company. I was also a chairman of teh comitee for qualification exams which were mandatory for people who wanted to open the screen printing, bt did not have the required qualifications. I also wrote several tutorials so they would have something to learn from, but never got around to writing a proper book. We were also producing screen printing machines and equipment, but that was all decades ago. People left several good advices below which I think are worth checking. I'd just like to mention a couple of details: - With proper technique it is posible to coat the creen with photo sensitive emulsion so that you'll be able to achieve better results than with photo polimer film. You can apply several coats, first applying a coat or two to the bottom side, and continue applying several more from the inside. If you do this, you may consider drying the emulsion with frame in horizontal positition, so it doesn't ooze sown the screen. This way you can get the coat thick enough to avoid the screen texture participate in the actual sharpness of the developed image. I suppose you can also buy photo sensitive films with different thicknesses, and thicker ones could give similar results. Using this approach, we were able to print extremely fine details, for etching and similar jobs. - We were also using room heaters in a big cupboard where the screens were hung. We did kill more than a couple a year, because the cupboard was kept almost completely closed, but it shortened the drying times dramatically. - You did not mention that the image is opened using hot water, or do you actually use cold water for this? Polymer films were usually opened using 40oC water, but we mostly used teh film which was first exposed, then developed using hydrogen peroxide and hor water, and only then applied to the screen usig a roller. There are probably many new products I don't even know about. - If you are using laser printer to make an artwork, you may put the printed paper in a low cardboard or plastic tray together with a bit of paper or any tissue soaked in acetone and cover it, and the acetone fumes will cause the print to be much blacker and opaque. Inkjet prints should behave the same. Edge definition is better after doing this, too. - No other printing technique utilizes such a vast array of different inks, from two component heat treated ones for metal and glass, to the rubber based expanding ones for textile. But in my experience, the most verstile ink, which we could use on plastic, wood, textile, and pretty much anything else except metal and/or glass, was the PVC solvent based one. It was the least healthy, too, unfortunately, and I have no idea if it is still sold, but it lasted decades on t-shirts and literally everywhere.
To whomever is watching this still. One thing drew my attention - Ben, you say that you can use plain old tracing paper, but it tends to jam in the printer. I've been doing printed circuit boards at home for several years now, and the trick I use is I tape a piece of tracing paper onto a sheet of regular printer paper with a piece of masking tame (minimum glue residue). You just have to tape only that side which gets fed into the printer - leave the other 3 loose. Works wonders for me. Also, wetting the tracing paper with something like WD-40 makes it almost clear - might also help with that contrast around the edges.
people are really sleeping on this guy and messing up hardcore. This fella absolutely makes the #1 best videos on youtube. This, this is what society needs.
Haven't screenprinted in 20 years, only thing new was the photo film. We coated screen with emulsion, took forever to dry. Once used a streetlight for the actinic light source to burn them. Great video. Thanks 👍
Very informative! I worked at a sign shop in Australia that did commercial screen printing for sign panels. They would coat the screen with a scoop coater in the shop with all the lights on then put a fan on it. They would then position the stencil onto the dried screen and put it outside in the sun for a few hours! So yes, this emulsion is not very light sensitive!
One thing that helped me tremendously was just seeing how someone made and used a test pattern to determine exposure times. It's a bit "simple" for someone like Ben, but for a dumb guy like me it made a big difference. I finally learned that most of my problems with dry film photoresist were due to over exposure using the Sun as a UV light source. My exposure times for Dupont Riston t215 film are 3-4 seconds for maximum resolution. It would probably be detrimental to try the same technique for this application, but I found it helpful to use a very light oil like triflow to get my transparencies as close as possible against photoresist while etching boards. I haven't been very successful using glass to compress this kind of stack. Maybe if I had a thick piece of foam as shown it would be different. There is no way I could find to effectively compress a stack between two sheets of glass. I was using the cheap sheet glass from Lowe's. I managed to break a couple sheets trying to do some larger double sided exposures. One other cheap a dirty way to do text may be to simply use photoresist film on thin wall aluminum (can) material. I've been goofing around with making my own solder mask stencils by stripping the outer coating of a soda can and using dry film. If I scale my image right I'm pretty sure I can render some 6-8 point text. I can do 0402 passives and TSSOP-20 footprints. I am going to try some text one day soon. I think the choice of font will be the most critical factor. I'm mostly looking to create a designator mask for boards. I've still got to master my soldermask technique first, but then I'm planning on trying this. I've been collecting Arizona Tea cans for base materials. I just use my typical PCB etchant of Hydrochloric Acid/Hydrogen Peroxid to etch the aluminum can too. The real trick is to undersize everything and plan for the etchant working in both the vertical and horizontal space around any exposed areas. I figured I'd just use it as a true stencil with a sprayed substrate. Anyways...thanks for the upload and tips. -Jake
I worked in a screen printing shop in the 70's I did simple screen printing that used hand drawn razor cut kraft paper letters as the resist - picked up onto the silk at the first squeege of ink. Single color mostly, large-font food store sale marquis :-) Limited run as you can imagine 200 -300 per set up. And very simple water based ink!! I never met the guy who cut the letters but I heard about it if I destroyed one or two. :-) I had a gander at the huge beam mounted large format Process Camera to produce transparencies. ...breathtaking. That camera was just gorgeous. Cambo on steroids Hadn't given it a thought till your upload :-) I do remember the smell of some of the polyester? ink of the day.
Ah yes, hand cutting stencils....so glad low cost, wide format inkjet came along!! I never did text, I just wasn't good enough, unless huge letters. I did know some art guys hand cutting 30-40 point text..I just didn't have the skill or the patience. I would love to have one of the 'smaller' cameras, just as a conversation piece. The news room ones were mind blowing...I have seen smaller cars........
Very nicely done! Being a university trained mathematician I really appreciate the technical depth you provide in your videos. Being a watercolor artist and sometimes print maker I found this analysis to have been the best I have come across. Thank you for your many efforts!
The 'Induction' period with 2 component inks (epoxy or polyurethane) is to allow the inks to de-gas after mixing. 30 minutes is a pretty standard de-gas time in ink mixing when dealing with any ink but applies mostly to 2 part inks and coatings. This may not have been properly explained in the data sheet. Hope this is of some use.
@@Asdayasman Its possible (either way :) never tested it, with screen printing as it is a shear deformation process keeping the bubbles low is important and more so in ink systems that cannot incorporate silicone de-foamers , typically epoxy inks used in PCB production cannot use silicone defoamers and due to their viscosity (thickness) bubbles dont release quickly. A little heat can also be applied but has to be below the curing temp. I could go on for ever but it gets boring :)
@@Asdayasman You left him in too long, you want to keep it under a minute. See Chapter 1 of the Bioastronautics Data Book: ntrs.nasa.gov/search.jsp?R=19730006364
I was researching how to do fine line printing on glass. You saved me so much time and effort and disappointment. Thank you very much for the effort expended producing this very fine video.
I've been learning to screen print for about 3 months now and I have so say, this was incredibly thorough and went over basically everything I've learnt. Great vid!
One of the few people I came across on YT that has a variety wider than what I dabble in. Detail definitely better too. In fact his detail is better than most.
i'm pretty sure i'm not gonna use screen printing in my life. however, watching Ben elaborately explain how it works is absolutely fascinating. i wish youtube had more dedicated in-depth content like this.
This is awesome, long ago (2005ish) I worked at a sign shop and they wanted to get into screen printing but didn't have the money for the equipment so I ordered some emulsion, 200 count screen material, scoop coater, ect, built my own frames and holder with registration pins, printed out the patters with black vinyl, cured it with a halogen work light.. Worked perfect from the first one. I was pretty amazed, made thousands of signs that way.
Just to thank you for producing these wonderful videos. Amazing! These are so good for anyone interested in making things either as a hobby or professionally. When you see how its done, it is less scary and gives anyone that tries a guide to follow and after you see the results for yourself, you learn you can make most things, a prototype, a project, something you can say I made that. Top job and a big thank you.
You are one of the most valuable content creators in the entirety of UA-cam. You bring such an intense level of education to this platform I'm sometimes just in awe at how you manage to get into so many different fields and bring such cool educational projects to everyone. It rekindles that child-like passion for discovery.
Had to subscribe. If This Old Tony can get 500,000 subscribers, you certainly deserve them. This is just an amazing video. So much information. So many things the screen printing guides leave out. Thanks for documenting it so clearly.
Your channel is a perfect example of quality over quantity. Each video is a veritable tome of information with no 'wait until the next video for the final crucial step' bait.
i like it how for every Ben's video there is someone in the comments who does that specific thing professionally all their life and they have something interesting to add.
Whow thanks for this super interesting video!! I'm hobby-screenprinting on shirts for > 10 years now and I always mess around with these transparent OHP-foils! We we're actually laughing about the guys that we just tagging their names on parchment paper to print in a youth club workshop back then. But it worked! And now I know even why! I would have liked to see you doing the measuring tho :D One thing I always thought was interesting but maybe also more specific to fabric then paper or other substrate: In the beginning you say one squeezes paint through the mesh. But where I learned it they always talk about "filling" the screen. And the substrate is then sucking the paint out of the screen itself. That's why you have the tension pressing down the screen on the substrate. When doing fabric you also have a very light adhesive fixing the fabric onto you printing table. Just so the fabric sticks MORE to it than to the paint in the screen! So again the fabric and take the paint out of the receding filled screen.
Just found this video - wow!!!!! I would love to see a focus on electroluminescent paint... Lo and behold, it's the next suggested video!! Honestly, your content is top notch. Rarely do I learn only one or two things from your presentations, usually my general knowledge is brought up in many areas, often in unrelated but relevant epiphanies. Thanks for your excellence sir
Fantastic. I too have come across the "nothing but t-shirts" phenomenon when looking for screen printing info, so your video was perfect (as are all your videos!). Thanks very much for posting this.
tried doing circuit boards with the screen printing kit from the craft store :/ Acrylic paints worked well for the 160ct the kit came with, got down to 0.5mm successfully. While I thought I was doing to increase resolution getting the 300 ct yielded way worse results with the same acrylic paint (tube), also not much paint available will stick to copper through a silk screen on the first shot. Did everything absolutely the wrong way. Wish I came across this video about 1.5 yrs ago.. Since then figured out how to get my 3D printer to scratch-engrave off blue layout spray paint (typically used for manual machining) off the copper foil clad raw PCB's for my isolation routing. After seeing your informative video, which I guess no one else from the industry bothered with sharing their valuable knowledge, I'm now considering breaking out the screen printing kit once again to give the prototype 2-sided PCB home manufacture another go. Thank you for sharing, subbed!
This reminds me of my old days using flat bed cameras where you needed to learn various nuances of the equipment and materials to get the best results and test prints/patterns were always something great when making film for printing plates which you could be masked off. There was also the benefit of using a vacuum/compressor bed on both the flat bed camera and UV plate exposer. I also did print some small run monochrome t-shirts (text and halftone) in the late 90's/early 00's but nothing requiring a high resolution and it was done using home kits that really weren't the greatest and often 2 small screens were used to make larger prints as you just found a solution to the problem you had. New sub ;-)
Nice video. I had actually never heard of the ready made emulsion sheets before. A tip for other people trying screen printing for the first time: A very low-cost way to expose screens which I've been using for 20 years now and still do is making a simple table out of a plate of glass and two trestles with a second hand face tanning lamp underneath. It can be on its back on the ground, it doesn't have to be directly under the glass. Throwing a sheet or blanket over the whole set-up when not exposing in a dark room helps. Placing a heavy enough book (or two) on top also works fine. Instead of putting the foam in between, which I find tends to curl up on the sides and therefore doesn't push down enough on the sides of your screen and design. Then I expose for about four minutes (using scoop coat emulsion and vellum). This will vary a bit according to the strength of your lamp, but generally around three to four minutes is enough. All emulsions I have used btw dry in one or two hours when put in a dark place with a simple blow dryer, but the conditions in my shop are probably different then yours. A whole day though seems long to me. I hope this helps someone. Happy printing!
This is great. I silkscreened some t-shirts a long time ago. I didn't know half of this. I looked into doing it again a few years ago and didn't find anything this organized. Thanks. Stretching the screens isn't that difficult. Your recommending buying pre-made screens which makes sense if your goal is just to do silkscreening. But stretching the fabric is easy to learn and has myriad applications. Back in college in about 1978 I watched an art student (Hi Eric O!) stretching a canvas- stapling the fabric onto the frame. I've been using that single lesson at least twice a year ever since. Just the simple concept of how to get out all the wrinkles is very useful. (Heavy duty 'pet proof' window screen can support your weight from replacing a mesh office seat to a cot). Also to clean up epoxy, usually vinegar works fairly well. Of course I don't know how it would work with the epoxy paint and the screen materials. One issue you won't have run into yet, is if you do a large run of printing, or make a few prints, clean your screen to use again, the edges of the mask will begin to deteriorate. Finally, your resolution issue just might be a factor of your large light source. It could also be level (intensity and/or length) of exposure. A point source should be better, but what I know about contact printing in photography... is that the size of the source isn't that important. Edward Weston just used a bare lightbulb about four feet above. What you're doing here in photography we'd call lith printing, no grays, just white or black. Exposure issues seem inconsequential....until they're a problem. You seem pretty methodical. While I'm procrastinating getting on the treadmill... Andy Warhol is famous for his silk screen paintings, I'll bet he never made any of them by himself. He had others make them, and he didn't pay them very well. Gerard Malanga got fed up and moved to Italy. He was short of money, so he thought, why not make some bootleg Warhols? He brought his 'Warhols' to a gallery who was happy to show them...but a little suspicious. So the dealer called the Factory in NYC. Warhol assured the dealer that they were indeed genuine....but send the check to me....
Its great to see you explaining how easy it is to do this with the right stuff. I used to manage a development thick film lab and do exactly this. Excellent information
Oh screen printing is fun! It's been a while but I experimented with it a bit a few years back. I went through arts & crafts books in the library to get information and my equipment was really shabby. I got my screen from a printing class that would've thrown it away cause it had holes near the edges. Good enough for me. An interesting hack I got from one of the books was to use black tea to increase adhesion of the photosensitive - the tea is high in tannines (I think that's the right word) which is great in this regard. Just use it after cleaning. As for inks: I used artists acrylic paint with a special additive that you can order at artists supplies. It makes the ink dry slower, which is quite handy in case of acrylic paint and also changes its consistency. This keeps everything water based, which was important to me and also allows you to experiment with the consistency of the paint. Either way. Great video! It's really worthwhile to experiment with screen printing, even if the results are not super detailed - everyone go and try it! :)
I take a screen printing class last year. I just print my artwork to regular 70 gram HVS paper using my inkjet printer and then brush the paper with cooking oil to make it transparent. Works better than all my classmates, which mostly using expensive ready to use kit. My teacher is so impressed with mine even though I didn't do exactly what he told me to (using laserjet printer).
I think you just solved the problem with the UV exposure printing machine thingy I'm building, I need much more pressure on the paper. Thank you so much!
If your dealing with solids like PCB/Photoresist just use a light oil like bicycle chain lube between the transparency and photoresist. Once the air bubbles are squeegeed out it will stay remarkably closer than anything I was able to achieve with glass and pressure. I picked that tip up from another YT'er and saved it in a playlist under PCB Fab.
That was funny to watch... Great job, spectacular explanation! I've been screen printing for nearly 20 years. Graphic printing, fine art printing and garment printing. I even taught a continuing ed class once and used your rubbermaid tub method. lol. Way under equipped. lots of fun. Screen Printing (Serigraphy) takes a great deal of time, patience, attention to detail and good studio practices. Clean up, clean up, clean up... But if you can master it you can do amazing things with it.
"Old Fashioned Direct Emulsion" - I've been screen printing for fifty years, in 1972, the "Old Fashioned" photo imaging was a gel coating on film that required a hydrogen peroxide with water for development. Back then Direct Emulsion was about 33-40% solids so the 'sawtoothing with the fabric' was far more distinct. Now Direct Emulsion is far more durable and about 60% solids. Xcellent video.
For UV PCBs I've always used tracing paper - the key to avoid jams and crinkling is to use the heaviest stuff you can get - minimum 90gsm. This stays pretty smooth and can do 600dpi, for 10/10 mil track/space PCBs. For high res you can get typesetting films made fairly cheaply - I've not done the latter for a while so not sure how readily available that service is these days as printing tech may have moved more to imaging direct to the printing plates.
Like so many techniques, it's been predominately done by people of the opinion "if anyone lets the world know how we do this, we're out of the job"? edit: I mean to say, thank you for documenting things in such a wonderfully accessible way
Amazing, thank you so much, just started screen printing and needed to watch this! Very exciting to learn about the possibilities of using other paints and surfaces too
Nice introduction to the whole process. All new to me, but very interesting. One of my hobbies is restoring old electronic test equipment. Often the front panels are worn or rusty, and it's a delicate balance between cleaning and not destroying the remaining printing. I can see how one might scan a stripped down front panel for the original artwork, really clean and refinish the panel, sharpen up and restore the artwork and reprint it. Even though I usually restore for function, restoring for appearance would be a fun new challenge.
Great video. Made screens for a PCB manufacturing plant. For the UV exposure we had a vacuum table. Making screens inst hard if you get frames that are able to be stretched, just takes a while to get the hang of getting it on right and getting the right tension across the whole surface. Also for making drying times shorter, we just put the frames in a holder in front of a box fan setup. They'll usually dry in an hour or so. You can also shop vac the water off the emulsion after it sets for a moment if you have a nice smooth tool for the job, just to make sure it doesnt pop the screen.
Great amount of information and I'm happy that it's not from a "pro". Much easier to understand and I felt like I was getting solid info without missing anything. Thanks!
Motivated by your success here, I tried a variation on the technique, using a 3D resin printer as both the exposure stencil and light source. A 50 micron thick 3D model of the stencil is loaded as a print, and then the screen is simply placed atop the printer in place of the resin bed. With good screen to contact to the printer glass (as you demonstrate), I got very similar detail, if not better than you did here. Thanks for sharing your process!
Small note, regular glass tends to block uv light. I would be sure to measure the output through any glass you use. In the tanning industry, we use special acrylics to pass uv light.
Oh how i needed this to show my father when he was setting up a flat membrane keyboard printing and overlay business way back when. 10 years doing the same method and he never allowed us to improve it.
My dad had a small product idea for a travel pillow that required screen printing as a kid. I remember learning a lot of these things as a kid from him. Good times!
Someone may have already mentioned this. But with a halogen work lamp for contractors and garage spaces. If you take the uv filter off. It use to set the emolsion I was using up in a max of 1min. The time was so short. I actually had to time it. If I waited too long, I would lose line definition on fine details. Awesome video as always good sir.
When trying to do high resolution printing you can really go down a rabbit hole on that one. There are combinations of screen and emulsion that perform better. Not just screen number or the like but the actual screen material and emulsion can make a difference. That gets into high end manufacturing as well. I never got into enough to help but it is out there. What you are doing is perfect for folks like me though.
This takes me back, when I was doing screen management at a shop we never needed to cure for more than 5 minutes though, and that was with fairly high detail. We used laser printed transparencies at 600dpi and supported up to 8 layers with good alignment. Most jobs used a backing layer and 2-4 colours. You are absolutely right about the matt separation distance causing problems for exposure, but using a paper matt causes too much diffusion as well so I can't recommend unless it's for learning. Oh, you should cover the ink curing process if you can, it affects longevity and durability especially for cloth prints.
Printer here: A screen is usally named (mesh count per inch - single thread thickness) so a 120-34 screen has 120 "strings" per inch and each string is 34micrometers thick. That thread thickness also determines sceen thickness (twice 34) and the thicker the screen, the higher the paint-canal is, wich means more paint per mesh-opening. On Exposure: And also regarding the paper as a medium to transfer the image... The ink used in general printers is letting light through, even when you print twice on top of each other. If you hold a bright small light (phone flash) against your black layer printed.. you SHOULD NOT be able to see the light through. If you do, all your resolution wont help, your exposure times go up, but at the same time you lose the harsh edges. (wich you need to print clearly!) and might not even be able to wash out the screen. You want the shortest exposure possible, with the brightest light you can achieve on a private scale, with the most non-translucent black to begin with. Thats why your screen got "stubborn" Don't use pressure washers to free up the screen though. You'll lose the "pixels" that only hang onto the mesh on the edge., but they make the resolutions o much better. And dont use paper(it might let through more UV-light, but the fibers scatter the light thousands of times before letting the light escape on the other side, if at all, leading to unwanted exposures on non-image areas, leading to lower resolution. Use film. Maybe even these overhead-projector films. The weight: Nice Idea if you have a flat lightsource that can withstand light. =) Cheerio
I know you were looking for image integrity being retained in the process and that is often important. On the other hand if you don't need the output to be without loss then a hack I tried with respect to the actual screen itself gives pretty good results. Specifically I built my own frames and rather than apply commercial screen I tried 'dollar store' shear curtain material. In my experiment I wanted a painterly feel to the image. To achieve this I thinned SpeedBall's drawing fluid and painted on a floral design in a manner similar to one of my watercolor paintings. I then used SpeedBall's screen filler followed by, once dry, washing out the drawing fluid. At this point I looked through the screen and decided the edges in the image were a bit too well defined and giving more of a coloring book or poster feel to the image than the look of a painting. I then grabbed a brush and a bottle of white inexpensive acrylic paint and brushed it into the image to break up the continuity that was giving the coloring book look to the image. I then ran a print. It was gorgeous and looked like I had painted the floral design on the paper entirely by brush. Not only did my lines and fields of color have the painterly look but the acrylic paint having only partially filled grid openings in the screen created beautiful high lights and over all a very good sense of depth was achieved in the image allowing the viewer to feel he or she was looking into three dimensional space.
Great video for starting on silkscreening. This pretty much sums up my 5 years experience silkscreening PCB. One thing to add. Very high resolution positive films can be obtained from imagestter. It makes a big difference for finer prints of line width of 8 mils or less.
Great helpful video, I’ve been screen printing for a few months now at my job using the Nazdar epoxy ink under mil-std-130. There are also variety of lead and cadmium based inks but they are all very sticky and quite messy.. as well as fun to work with. I am mainly parts marking so printing a large assortment of surfaces.
I'm a screen printer. When washing out the stencil, as soon as you get the emulsion whey, it is no longer light sensitive. After burning a screen, I would spray it with water and use my hand to spread the water over the entire image...both sides...the wash out the stencil in daylight with no issues. :)
Daylight as the light in the room....I wouldn't try washing out in direct sunlight. Wet emulsion is seemingly less sensitive but not, not sensitive. I coat and wash out under room lights but wouldn't want sunlight streaming into the wash out area. Definitely no need to wash out in a darkroom setting. Printer since '92
I used to work at a DVD Factory, this is how we printed the pictures on the DVDs. we would use UV lights in between each color with the ink. It would dry in literally 1 or 2 seconds for each color.
One of the worst things about screen printing in my 2 years of experience has been using different types of emulsion and capillary film and having to adjust the exposure times accordingly. It is really frustrating to burn out a screen, only for all your emulsion to pop out, leaving you to re-emulsify, reburn, adjust burn times, and try again (usually repeating this process a few more times until the exposure unit is set to the right time) thank you for the help!
I Screen print all the London Bus Destination roller blinds, we use 72 mesh count and the edge detail on curves is suprizingly sharp. really small text you need finer mesh but you can get fine edges on large text on a bigger mesh count ,also provides better ink coverage/opacity. 21 years experiance. Screen printer for life :)
You may not post videos as often as others but when you do, they're long and they are in depth. Every video you make is great, Ben.
@sei shin It probably averages 0.5-2 hours per minute of video. I've spent 10-20 hours learning about screen printing in this case, for example. This is another reason why I like the format of 10-20 minute videos in general -- it's information concentrate!
I was a bit sad when it ended.
I spent most of my life in our family run screen printing business. We did huge volumes (like, millions of prints a month on 6 12 color automated presses), and obviously had to invent techniques and learn a lot of stuff by trial and error. My job during my high school years was to make screens. That meant stretching them, coating them, shooting them, and cleaning them. I probably saw that life cycle of a screen 1000 times.
Right away I have to say - you weren't using the screen coating tool properly. You need to fill it with a bit less emulsion, then while the emulsion is till deep within the coater, you tilt the screen enough to be able to push the coater up to it so that you can tilt the coater to the point where the edges are pushed into the screen. Then you tilt the screen and coater together until the emulsion is just touching the screen, and lift up. As you near the top edge of the screen, you tilt back to the starting angle, rolling the edge of the coater back so you can feather out the edge of the emulsion to avoid making a bead. Do the same for the other side, and you end up with thin layers on both sides with no beads.
Aside from that , you've done a great job at describing the process for people who have never heard it.
That said, some other things to consider:
Coating the screens properly makes for screens that produce higher resolution prints and last a lot longer than using the more expensive emulsion sheets. They last longer because the mesh is fully captured by the emulsion layers on both sides of the screen. Those layers are also thinner than the emulsion sheets, which means you get more crisp stencils. The light you use to expose the screen is prone to creating shadows that spread (especially if the light comes from a single point). The thicker your stencil, the more your shadows spread, producing a more "blown out" print than a thinner stencil.
You also want as little amount of gap between the screen and the substrate you want to print on as possible. You need some, but the larger the gap, the more than print will be distorted. It's not a big issue on single color prints, but if you're doing multiple colors and need them to have tight registration, too much stretch is a nightmare.
300 micron is great, but you can get as small as 50 micron with the right combo of mesh, emulsion, ink, and process. Back in the day, we used to do 4 color process printed on fabric that looked as good as a modern CMYK printed magazine image. It wasn't easy, but it's totally possible.
Thank you for your informative post. Could you recommend a mesh count, emulsion and ink for very fine line drawings. I have tried with 300 mesh but not getting the fine line/detailed high resolution results I need. I am not sure if its my printer, the emulsion, or the ink I am using.
This comment should be pinned. Super informative
@@schediastriamoda7459 Curious if you found a solution. Curious what you are trying to reproduce. A 300 mesh with 1 thing coat each side, is capable of very high resolution. Art file, film out put, screen 'burning' (exposing) print technique, all factor into the final print quality.
My impression is most 'amateurs' (no offence intended) just don't have all the parameters together at once.
300 DPI file printed Black, and I mean BLACK on CLEAR film tightly sandwiched with properly coated screen and exposed with a proper light source.
NOT a grow bulb (fluorescent), NOT a work light. The exception to the grow bulbs is IF they are metal halide, then OK. I use a home built exposure table with a 1000w metal halide and it burns a very good screen.
I print tshirts for a living and happy to help anyway I can.
Tell us more about what you are trying to print, and more about what 'stuff' you have..screens, film output, exposure etc
Cheers
This and @Joe Shmoe 's comments are fantastic! Thank you both so much :). As a photographer with darkroom experience, this cleared up much of my doubts which remained after the main video :) .
Please consider doing your own videos on the topic; I'd love to see them.
I dove into the comments to see if anyone talked about point light sources (like the sun) vs diffused light sources (such as the UV table in this video).
Point light sources are definitely more appropriate for fine detail as diffused light sources inherently reduce shadow sharpness.
Having grown up in the printing (textiles and paper) industry, this takes me back a way.
In a hurry we would be able to get screens dry after coating within 15 minutes or so using a hot room heater, we had a yellow light room with screen racks to hold 50 screens at a time while drying.
When exposing screens, we built a vacuum frame, glass front with rubber backing, the artwork would be placed on the screen in register across a number of (ink) colours then placed in the vacuum frame 4 screens at a time, glass closed and latched and vacuum turned on. The vacuum means that all air gaps are taken out and the artwork is tight against the screen.
Our light source was a carbon arc lamp, with 3/4” carbon electrodes sat about 4 feet away from the vacuum frame.
Hope this is helpful to someone :-)
We also built our own screen stretching machine, which was able to tension up 4 screens at a time :-) it used 24 pneumatic cylinders and overcentre clamps to bite on to the mesh.
We would usually have a dead zone 20mm to the left and right, our off-contact approx 2-3mm being aware that any extra stretch can distort the artwork out of scale, especially if it’s non-linear stretch, more in X than Y
@@JBFromOZ I used to work in the printing industry when it was all still about film in the 80s and early 90s. I used to expose printing plates with a NuArc carbon arc plate burner. Don't breathe the fumes! :) We later went to a pulsed Xenon burner.
@@HackaweekTV I still run an old heidelberg GTO built in the late 60's - we still have the xenon plate burner set up for use with the old negatives. Our new plates are actually inkjet printed onto metal plates with an Epson wide format printer; it's not as durable as the UV plates, but the whole assembly fits in the same footprint that the film processor alone took up.
Years ago when we were still using a carbon arc light to expose the screens, we would turn the arc on for just a second and turn it off so that we could light our cigarettes on the end of the glowing hot carbon electrodes. Good times.
I agree, those vacuum frame exposure machines do an amazing job at getting the pressure right for a sharp image.
Just a couple of tips:
You can use standard cartridge paper for exposing a screen, a light coating of vegetable oil will make make the paper translucent, once you wipe all excess oil away this works brilliantly.
To get dark blacks on a printer use the CMYK values 60 40 40 100, this is known as 'rich black' among printers and will get you the most contrast in your prints.
Great video!
Thank you so much!!!
"This passes more UV light than the clear plastic does. I've measured it." Of course you have! I've come to expect no less from you - I've only recently discovered your channel but I'm continually amazed by the breadth and depth of your knowledge, experience and the lengths you go to really understand things. Brilliant.
This video is absolutely the kind of resource that the internet needed for high-res printing on substrates which aren't t-shirts. I wish you'd put this video together about a year ago!
We went through a lot of experimentation in terms of applying emulsion, exposure times, screen setup, etc and came to many of the same conclusions that you outlined in this video. Even after all that I still feel like I've learned a lot from the depth and accuracy of the information you provide in this video!
We'll definitely be giving the emulsion-film a shot next time we have a batch of screens to make. I feel like it will greatly increase the success and resolution of the screens we make to print on our guitar pedals.
I looked all over the Internet about 4 years ago looking for info on making high res screens for small electronics panels and finally gave up. You have pulled it all together and given me enough info to at least get started and make a stab at it. Thanks so much Ben for your excellent info which was explained very well. You remain my favorite Professor !!
I've watched a million videos on UA-cam about the silkscreening process, and this one is by far full of the most useful and valuable information. The narrator wastes no words. Tons of knowledge gems in here. Thank you!
never fails, always an interesting topic / presentation. How long till the HD tshirts?
how in hell, i read this with TOT's voice in my head
When i opened this video، i remembered to watch your last video lol
I think I saw your hands in this video, or perhaps its just deja vu or some of your magic dolls got to him too.
scientists are having trouble figuring out how to get the TFTs on the fabric... and dont even get them started on the glass :^)
I'm kind of expecting to see one more electroluminescent paint follow up video after this.
For about 15 years I've been using Pictorico OHP transparency film and inkjet printer for making my screen transfer positives. The sheets have an emulsion on one side that holds a high saturation of ink, so you can make a very dense image.
Fully agree. I've been using "Bab's" Transparency film for a few years, I'm pretty sure it's rebranded Pict film or very similar. It really does make the densest saturations I've ever seen. The vellum prints he made looked just like the ones I struggled with for a while before I found Bab's. My exposure times went down 3-fold as well.
Are those emulsion sheets? Cuz im looking on ebay an there just clear
I never thought about having to leave a gap between the screen and the part you're printing on. This way they only touch for a second when your pushing the squeegee then separate again.
I'm sure you've helped a lot of people with this well thought out video.
Synth nerds (and people who make DIY test equipment) are always looking for ways of making better looking front panels.
I watched about two dozen videos about this topic, but this one is officially the best and explained it ALL!!!! THANK YOU!!!!
I wish I had this video about eight years ago when I took three college classes on screen printing. So much more concise so much more to the point I’m actually going to go out and buy a couple screens right now because I feel like you did such a good job on that video. Thank you
I plan to screen print the markings on the instrument panel of my homebuilt airplane. Like you said, all the info out there is for t shirts. This video is EXACTLY what I was looking for. Very detailed. Couldn't ask for a better tutorial. Thank you so much!!
Applied Science is going to the moon next?! Awesome!
sorry but we lost that technology, as we used to be able to do so in a nano-second.
HAH! You sheeple actually believe in the moon? What a bunch of rubes!
pretty straightforward
@@Falcrist lol
This is a really informational video and I thank you a lot for it. Since I was making my own PCB's not so long ago, I can give all of you a little hint. When you print your design on a "paus" paper, as mentioned in the video, you can increase the contrast dramatically by laying the design flat with toner facing up. All you need is a shoe box cover and some pure acetone. Drip some droplets of acetone on the inner side of the cover and then place it over the design for a couple of minutes. The difference will really be obvious, if not dramatic.
Learned two things:
1. How screen printing works
2. I am never going to do this
lots of things in done in this channel would be really cool and interesting to do, they take quite some money and space though :p
funny, and I will try it FOR SURE now! ;-)
Umm, never say never :-)
@@Don.Challenger Of course not :) It was just a joke about the complexity and difficulty of this procedure.
Yes, I know ElM, when I was a young fellow I silkscreened wrestling poster as a part time job until the fumes had me riding my bicycle home along building walls but back the next day - and I'm still interested in the process. And my father spent much time perfecting his own ability making PCBs for short run production. I kept way from photography until digital came around as proficiency then didn't require the chemistry degree. And of course technique in small run is greatly different from production and mass market requirements - each branch spawning its own complexity of knowledge. The video and comments here show this wonderfully (and on this channel generally)..
We have some kind of set up like this at work. I am an aircraft mechanic and sometimes we have to etch our tools with our name or initials.
We start by printing initials out on a transparency and then we lay this on top of a blue gel sheet (It seems to be a fine mesh sandwiched in between two sides of this emulsion stuff). We put that under a UV light for two minutes, (with the print out on top) to expose. We scrub the unreacted portion off with a sponge and what appears to be just water. Now you have a similar thing. However, we use this to electrochemically etch our tools.
The etching device seems to be a one to one transformer that plugs right into the wall. The secondary coil is hooked up to an alligator clip and one side is hooked up to this apparatus that holds a felt pad with a metal screen under it. YouCan put on different types of chemical in order to etch into different types of metal. You can also put a diode in series with the alligator clip to change it from AC to DC. This has the ability to make a black oxide rather than etch into the metal. Anyway, you apply at the alligator clip to a part of the tool or a sheet of metal where you lay the tool on. You lay your pattern down on the tool and press the chemically-wet etching pad on the film. In 10 seconds or 30 seconds it makes a pretty decent mark.
It makes really nice metal etchings. It’s better than taking a vibropeen etcher to it... it just takes longer. This set up is a kit that we got but I can’t remember the name.
Also, how durable are the emulsion patterns after you make them? I hear about a useful life of certain patterns that people make before they have to make another pattern (like scraping the squeegee over it a bunch of times will wear it out or something)
As a screen printer for over 13 years I learned a lot from you today 🔥🔥🔥🔥
Great informative video. And just as a couple of other people who left the comments, I have also spent probably half of my life working in my screen printing company. I was also a chairman of teh comitee for qualification exams which were mandatory for people who wanted to open the screen printing, bt did not have the required qualifications. I also wrote several tutorials so they would have something to learn from, but never got around to writing a proper book. We were also producing screen printing machines and equipment, but that was all decades ago.
People left several good advices below which I think are worth checking. I'd just like to mention a couple of details:
- With proper technique it is posible to coat the creen with photo sensitive emulsion so that you'll be able to achieve better results than with photo polimer film. You can apply several coats, first applying a coat or two to the bottom side, and continue applying several more from the inside. If you do this, you may consider drying the emulsion with frame in horizontal positition, so it doesn't ooze sown the screen. This way you can get the coat thick enough to avoid the screen texture participate in the actual sharpness of the developed image. I suppose you can also buy photo sensitive films with different thicknesses, and thicker ones could give similar results. Using this approach, we were able to print extremely fine details, for etching and similar jobs.
- We were also using room heaters in a big cupboard where the screens were hung. We did kill more than a couple a year, because the cupboard was kept almost completely closed, but it shortened the drying times dramatically.
- You did not mention that the image is opened using hot water, or do you actually use cold water for this? Polymer films were usually opened using 40oC water, but we mostly used teh film which was first exposed, then developed using hydrogen peroxide and hor water, and only then applied to the screen usig a roller. There are probably many new products I don't even know about.
- If you are using laser printer to make an artwork, you may put the printed paper in a low cardboard or plastic tray together with a bit of paper or any tissue soaked in acetone and cover it, and the acetone fumes will cause the print to be much blacker and opaque. Inkjet prints should behave the same. Edge definition is better after doing this, too.
- No other printing technique utilizes such a vast array of different inks, from two component heat treated ones for metal and glass, to the rubber based expanding ones for textile. But in my experience, the most verstile ink, which we could use on plastic, wood, textile, and pretty much anything else except metal and/or glass, was the PVC solvent based one. It was the least healthy, too, unfortunately, and I have no idea if it is still sold, but it lasted decades on t-shirts and literally everywhere.
To whomever is watching this still. One thing drew my attention - Ben, you say that you can use plain old tracing paper, but it tends to jam in the printer. I've been doing printed circuit boards at home for several years now, and the trick I use is I tape a piece of tracing paper onto a sheet of regular printer paper with a piece of masking tame (minimum glue residue). You just have to tape only that side which gets fed into the printer - leave the other 3 loose. Works wonders for me. Also, wetting the tracing paper with something like WD-40 makes it almost clear - might also help with that contrast around the edges.
people are really sleeping on this guy and messing up hardcore. This fella absolutely makes the #1 best videos on youtube. This, this is what society needs.
Haven't screenprinted in 20 years, only thing new was the photo film. We coated screen with emulsion, took forever to dry. Once used a streetlight for the actinic light source to burn them. Great video. Thanks 👍
Hahahahhaha "pretty straightforward, but going to the moon is also pretty straightforward if you just say we blast off and then we land". Loved it
My dad always used to say this about playing the flute. "yeah, you just blow down the end and wiggle your fingers."
Very informative!
I worked at a sign shop in Australia that did commercial screen printing for sign panels. They would coat the screen with a scoop coater in the shop with all the lights on then put a fan on it. They would then position the stencil onto the dried screen and put it outside in the sun for a few hours! So yes, this emulsion is not very light sensitive!
One thing that helped me tremendously was just seeing how someone made and used a test pattern to determine exposure times. It's a bit "simple" for someone like Ben, but for a dumb guy like me it made a big difference. I finally learned that most of my problems with dry film photoresist were due to over exposure using the Sun as a UV light source. My exposure times for Dupont Riston t215 film are 3-4 seconds for maximum resolution.
It would probably be detrimental to try the same technique for this application, but I found it helpful to use a very light oil like triflow to get my transparencies as close as possible against photoresist while etching boards. I haven't been very successful using glass to compress this kind of stack. Maybe if I had a thick piece of foam as shown it would be different. There is no way I could find to effectively compress a stack between two sheets of glass. I was using the cheap sheet glass from Lowe's. I managed to break a couple sheets trying to do some larger double sided exposures.
One other cheap a dirty way to do text may be to simply use photoresist film on thin wall aluminum (can) material. I've been goofing around with making my own solder mask stencils by stripping the outer coating of a soda can and using dry film. If I scale my image right I'm pretty sure I can render some 6-8 point text. I can do 0402 passives and TSSOP-20 footprints. I am going to try some text one day soon. I think the choice of font will be the most critical factor. I'm mostly looking to create a designator mask for boards. I've still got to master my soldermask technique first, but then I'm planning on trying this. I've been collecting Arizona Tea cans for base materials. I just use my typical PCB etchant of Hydrochloric Acid/Hydrogen Peroxid to etch the aluminum can too. The real trick is to undersize everything and plan for the etchant working in both the vertical and horizontal space around any exposed areas. I figured I'd just use it as a true stencil with a sprayed substrate.
Anyways...thanks for the upload and tips.
-Jake
I worked in a screen printing shop in the 70's
I did simple screen printing that used hand drawn razor cut kraft paper letters as the resist - picked up onto the silk at the first squeege of ink. Single color mostly, large-font food store sale marquis :-) Limited run as you can imagine 200 -300 per set up. And very simple water based ink!!
I never met the guy who cut the letters but I heard about it if I destroyed one or two. :-) I had a gander at the huge beam mounted large format Process Camera to produce transparencies.
...breathtaking. That camera was just gorgeous. Cambo on steroids
Hadn't given it a thought till your upload :-) I do remember the smell of some of the polyester? ink of the day.
Ah yes, hand cutting stencils....so glad low cost, wide format inkjet came along!!
I never did text, I just wasn't good enough, unless huge letters. I did know some art guys hand cutting 30-40 point text..I just didn't have the skill or the patience.
I would love to have one of the 'smaller' cameras, just as a conversation piece. The news room ones were mind blowing...I have seen smaller cars........
Very nicely done! Being a university trained mathematician I really appreciate the technical depth you provide in your videos. Being a watercolor artist and sometimes print maker I found this analysis to have been the best I have come across. Thank you for your many efforts!
The 'Induction' period with 2 component inks (epoxy or polyurethane) is to allow the inks to de-gas after mixing. 30 minutes is a pretty standard de-gas time in ink mixing when dealing with any ink but applies mostly to 2 part inks and coatings. This may not have been properly explained in the data sheet. Hope this is of some use.
Could that time be lowered with a vibration table?
(Or if you're crafty, two high powered sex toys, some 2x4s, a sheet of plywood, and some vices).
@@Asdayasman Its possible (either way :) never tested it, with screen printing as it is a shear deformation process keeping the bubbles low is important and more so in ink systems that cannot incorporate silicone de-foamers , typically epoxy inks used in PCB production cannot use silicone defoamers and due to their viscosity (thickness) bubbles dont release quickly. A little heat can also be applied but has to be below the curing temp. I could go on for ever but it gets boring :)
A vacuum chamber is great for degassing.
@@ipissed Yeah but after giving my dog cheese, when I put him in the vacuum chamber he fuckin' straight up died.
@@Asdayasman You left him in too long, you want to keep it under a minute. See Chapter 1 of the Bioastronautics Data Book: ntrs.nasa.gov/search.jsp?R=19730006364
I was researching how to do fine line printing on glass. You saved me so much time and effort and disappointment. Thank you very much for the effort expended producing this very fine video.
I've been learning to screen print for about 3 months now and I have so say, this was incredibly thorough and went over basically everything I've learnt. Great vid!
One of the few people I came across on YT that has a variety wider than what I dabble in. Detail definitely better too. In fact his detail is better than most.
i'm pretty sure i'm not gonna use screen printing in my life. however, watching Ben elaborately explain how it works is absolutely fascinating. i wish youtube had more dedicated in-depth content like this.
This is awesome, long ago (2005ish) I worked at a sign shop and they wanted to get into screen printing but didn't have the money for the equipment so I ordered some emulsion, 200 count screen material, scoop coater, ect, built my own frames and holder with registration pins, printed out the patters with black vinyl, cured it with a halogen work light.. Worked perfect from the first one. I was pretty amazed, made thousands of signs that way.
im an artist whos been trying to find these steps for this medium in a cohesive order, I thank you for your contribution to the community
I've been watching your videos since when it was your name and not Applied Science. Thank you for uploading such detailed content. I love watching it.
Just to thank you for producing these wonderful videos. Amazing! These are so good for anyone interested in making things either as a hobby or professionally. When you see how its done, it is less scary and gives anyone that tries a guide to follow and after you see the results for yourself, you learn you can make most things, a prototype, a project, something you can say I made that. Top job and a big thank you.
You are one of the most valuable content creators in the entirety of UA-cam. You bring such an intense level of education to this platform I'm sometimes just in awe at how you manage to get into so many different fields and bring such cool educational projects to everyone. It rekindles that child-like passion for discovery.
Wasn't sure why i was watching this at first but toward the end i realized this is exactly the info i needed for a project. Ty
Actually i know exactly why i was watching this- because it's an Applied Science video.
Had to subscribe. If This Old Tony can get 500,000 subscribers, you certainly deserve them. This is just an amazing video. So much information. So many things the screen printing guides leave out. Thanks for documenting it so clearly.
This really made me appreciate how ingenuous of a technique screen printing is.
Your channel is a perfect example of quality over quantity.
Each video is a veritable tome of information with no 'wait until the next video for the final crucial step' bait.
i like it how for every Ben's video there is someone in the comments who does that specific thing professionally all their life and they have something interesting to add.
Whow thanks for this super interesting video!! I'm hobby-screenprinting on shirts for > 10 years now and I always mess around with these transparent OHP-foils! We we're actually laughing about the guys that we just tagging their names on parchment paper to print in a youth club workshop back then. But it worked! And now I know even why! I would have liked to see you doing the measuring tho :D
One thing I always thought was interesting but maybe also more specific to fabric then paper or other substrate: In the beginning you say one squeezes paint through the mesh. But where I learned it they always talk about "filling" the screen. And the substrate is then sucking the paint out of the screen itself. That's why you have the tension pressing down the screen on the substrate.
When doing fabric you also have a very light adhesive fixing the fabric onto you printing table. Just so the fabric sticks MORE to it than to the paint in the screen! So again the fabric and take the paint out of the receding filled screen.
Just found this video - wow!!!!!
I would love to see a focus on electroluminescent paint... Lo and behold, it's the next suggested video!!
Honestly, your content is top notch. Rarely do I learn only one or two things from your presentations, usually my general knowledge is brought up in many areas, often in unrelated but relevant epiphanies.
Thanks for your excellence sir
Fantastic. I too have come across the "nothing but t-shirts" phenomenon when looking for screen printing info, so your video was perfect (as are all your videos!). Thanks very much for posting this.
tried doing circuit boards with the screen printing kit from the craft store :/ Acrylic paints worked well for the 160ct the kit came with, got down to 0.5mm successfully. While I thought I was doing to increase resolution getting the 300 ct yielded way worse results with the same acrylic paint (tube), also not much paint available will stick to copper through a silk screen on the first shot. Did everything absolutely the wrong way. Wish I came across this video about 1.5 yrs ago.. Since then figured out how to get my 3D printer to scratch-engrave off blue layout spray paint (typically used for manual machining) off the copper foil clad raw PCB's for my isolation routing.
After seeing your informative video, which I guess no one else from the industry bothered with sharing their valuable knowledge, I'm now considering breaking out the screen printing kit once again to give the prototype 2-sided PCB home manufacture another go. Thank you for sharing, subbed!
Ahh, the morning doesn´t getter much better than this, a new video from Ben and a cup of fresh coffee :)
Thanks a lot!
I used to screen print for a living and I have to say your video is pretty thorough.
WOW all that information and for free.... thank you so much.
This reminds me of my old days using flat bed cameras where you needed to learn various nuances of the equipment and materials to get the best results and test prints/patterns were always something great when making film for printing plates which you could be masked off. There was also the benefit of using a vacuum/compressor bed on both the flat bed camera and UV plate exposer.
I also did print some small run monochrome t-shirts (text and halftone) in the late 90's/early 00's but nothing requiring a high resolution and it was done using home kits that really weren't the greatest and often 2 small screens were used to make larger prints as you just found a solution to the problem you had.
New sub ;-)
We can lay-off every UA-camr and hire this guy for every subject.
Nice video. I had actually never heard of the ready made emulsion sheets before. A tip for other people trying screen printing for the first time: A very low-cost way to expose screens which I've been using for 20 years now and still do is making a simple table out of a plate of glass and two trestles with a second hand face tanning lamp underneath. It can be on its back on the ground, it doesn't have to be directly under the glass. Throwing a sheet or blanket over the whole set-up when not exposing in a dark room helps. Placing a heavy enough book (or two) on top also works fine. Instead of putting the foam in between, which I find tends to curl up on the sides and therefore doesn't push down enough on the sides of your screen and design. Then I expose for about four minutes (using scoop coat emulsion and vellum). This will vary a bit according to the strength of your lamp, but generally around three to four minutes is enough. All emulsions I have used btw dry in one or two hours when put in a dark place with a simple blow dryer, but the conditions in my shop are probably different then yours. A whole day though seems long to me. I hope this helps someone. Happy printing!
This is great. I silkscreened some t-shirts a long time ago. I didn't know half of this. I looked into doing it again a few years ago and didn't find anything this organized. Thanks. Stretching the screens isn't that difficult. Your recommending buying pre-made screens which makes sense if your goal is just to do silkscreening. But stretching the fabric is easy to learn and has myriad applications. Back in college in about 1978 I watched an art student (Hi Eric O!) stretching a canvas- stapling the fabric onto the frame. I've been using that single lesson at least twice a year ever since. Just the simple concept of how to get out all the wrinkles is very useful. (Heavy duty 'pet proof' window screen can support your weight from replacing a mesh office seat to a cot).
Also to clean up epoxy, usually vinegar works fairly well. Of course I don't know how it would work with the epoxy paint and the screen materials.
One issue you won't have run into yet, is if you do a large run of printing, or make a few prints, clean your screen to use again, the edges of the mask will begin to deteriorate.
Finally, your resolution issue just might be a factor of your large light source. It could also be level (intensity and/or length) of exposure. A point source should be better, but what I know about contact printing in photography... is that the size of the source isn't that important. Edward Weston just used a bare lightbulb about four feet above. What you're doing here in photography we'd call lith printing, no grays, just white or black. Exposure issues seem inconsequential....until they're a problem. You seem pretty methodical.
While I'm procrastinating getting on the treadmill... Andy Warhol is famous for his silk screen paintings, I'll bet he never made any of them by himself. He had others make them, and he didn't pay them very well. Gerard Malanga got fed up and moved to Italy. He was short of money, so he thought, why not make some bootleg Warhols? He brought his 'Warhols' to a gallery who was happy to show them...but a little suspicious. So the dealer called the Factory in NYC. Warhol assured the dealer that they were indeed genuine....but send the check to me....
This is the most important screen printing video on UA-cam. Thank you very much.
Its great to see you explaining how easy it is to do this with the right stuff. I used to manage a development thick film lab and do exactly this. Excellent information
Oh screen printing is fun! It's been a while but I experimented with it a bit a few years back. I went through arts & crafts books in the library to get information and my equipment was really shabby. I got my screen from a printing class that would've thrown it away cause it had holes near the edges. Good enough for me. An interesting hack I got from one of the books was to use black tea to increase adhesion of the photosensitive - the tea is high in tannines (I think that's the right word) which is great in this regard. Just use it after cleaning. As for inks: I used artists acrylic paint with a special additive that you can order at artists supplies. It makes the ink dry slower, which is quite handy in case of acrylic paint and also changes its consistency. This keeps everything water based, which was important to me and also allows you to experiment with the consistency of the paint.
Either way. Great video! It's really worthwhile to experiment with screen printing, even if the results are not super detailed - everyone go and try it! :)
Super interesting! It remind me when I have learned screenprinting at school but never practice after that moment. Thank you for that deep review!
I take a screen printing class last year.
I just print my artwork to regular 70 gram HVS paper using my inkjet printer and then brush the paper with cooking oil to make it transparent. Works better than all my classmates, which mostly using expensive ready to use kit. My teacher is so impressed with mine even though I didn't do exactly what he told me to (using laserjet printer).
I think you just solved the problem with the UV exposure printing machine thingy I'm building, I need much more pressure on the paper. Thank you so much!
If your dealing with solids like PCB/Photoresist just use a light oil like bicycle chain lube between the transparency and photoresist. Once the air bubbles are squeegeed out it will stay remarkably closer than anything I was able to achieve with glass and pressure.
I picked that tip up from another YT'er and saved it in a playlist under PCB Fab.
hmm.. just to be honest one of the best channels out there! Thank you for your hard work and great presentation!
That was funny to watch... Great job, spectacular explanation! I've been screen printing for nearly 20 years. Graphic printing, fine art printing and garment printing. I even taught a continuing ed class once and used your rubbermaid tub method. lol. Way under equipped. lots of fun. Screen Printing (Serigraphy) takes a great deal of time, patience, attention to detail and good studio practices. Clean up, clean up, clean up... But if you can master it you can do amazing things with it.
"Old Fashioned Direct Emulsion" - I've been screen printing for fifty years, in 1972, the "Old Fashioned" photo imaging was a gel coating on film that required a hydrogen peroxide with water for development. Back then Direct Emulsion was about 33-40% solids so the 'sawtoothing with the fabric' was far more distinct. Now Direct Emulsion is far more durable and about 60% solids. Xcellent video.
For UV PCBs I've always used tracing paper - the key to avoid jams and crinkling is to use the heaviest stuff you can get - minimum 90gsm. This stays pretty smooth and can do 600dpi, for 10/10 mil track/space PCBs. For high res you can get typesetting films made fairly cheaply - I've not done the latter for a while so not sure how readily available that service is these days as printing tech may have moved more to imaging direct to the printing plates.
Like so many techniques, it's been predominately done by people of the opinion "if anyone lets the world know how we do this, we're out of the job"?
edit: I mean to say, thank you for documenting things in such a wonderfully accessible way
Amazing, thank you so much, just started screen printing and needed to watch this! Very exciting to learn about the possibilities of using other paints and surfaces too
You are one of the main reasons the internet doesn’t suck, imo \m/
Nice introduction to the whole process. All new to me, but very interesting. One of my hobbies is restoring old electronic test equipment. Often the front panels are worn or rusty, and it's a delicate balance between cleaning and not destroying the remaining printing. I can see how one might scan a stripped down front panel for the original artwork, really clean and refinish the panel, sharpen up and restore the artwork and reprint it. Even though I usually restore for function, restoring for appearance would be a fun new challenge.
Excellent explanation and clearly articulated. I'm anxious to see how multiple colors work.
Wow this is the video I've been looking for since the dawn of time! You're right, no videos on glass and metal which is what I've been looking for.
Great video. Made screens for a PCB manufacturing plant. For the UV exposure we had a vacuum table. Making screens inst hard if you get frames that are able to be stretched, just takes a while to get the hang of getting it on right and getting the right tension across the whole surface. Also for making drying times shorter, we just put the frames in a holder in front of a box fan setup. They'll usually dry in an hour or so. You can also shop vac the water off the emulsion after it sets for a moment if you have a nice smooth tool for the job, just to make sure it doesnt pop the screen.
Great amount of information and I'm happy that it's not from a "pro". Much easier to understand and I felt like I was getting solid info without missing anything. Thanks!
Motivated by your success here, I tried a variation on the technique, using a 3D resin printer as both the exposure stencil and light source. A 50 micron thick 3D model of the stencil is loaded as a print, and then the screen is simply placed atop the printer in place of the resin bed. With good screen to contact to the printer glass (as you demonstrate), I got very similar detail, if not better than you did here. Thanks for sharing your process!
Small note, regular glass tends to block uv light. I would be sure to measure the output through any glass you use. In the tanning industry, we use special acrylics to pass uv light.
Oh how i needed this to show my father when he was setting up a flat membrane keyboard printing and overlay business way back when. 10 years doing the same method and he never allowed us to improve it.
Great work. Very cut and dry, non-complicated breakdown of something notoriously difficult. Thank You!
My dad had a small product idea for a travel pillow that required screen printing as a kid. I remember learning a lot of these things as a kid from him. Good times!
Someone may have already mentioned this. But with a halogen work lamp for contractors and garage spaces. If you take the uv filter off. It use to set the emolsion I was using up in a max of 1min. The time was so short. I actually had to time it. If I waited too long, I would lose line definition on fine details. Awesome video as always good sir.
One of the best videos here on UA-cam EVER!
Thank you so very much.
Kind regards from Portugal.
Thanks for such an in depth and informative video. I'm interested in screen printing and found all of the hints and tips extremely helpful.
When trying to do high resolution printing you can really go down a rabbit hole on that one. There are combinations of screen and emulsion that perform better. Not just screen number or the like but the actual screen material and emulsion can make a difference. That gets into high end manufacturing as well. I never got into enough to help but it is out there. What you are doing is perfect for folks like me though.
This takes me back, when I was doing screen management at a shop we never needed to cure for more than 5 minutes though, and that was with fairly high detail.
We used laser printed transparencies at 600dpi and supported up to 8 layers with good alignment. Most jobs used a backing layer and 2-4 colours.
You are absolutely right about the matt separation distance causing problems for exposure, but using a paper matt causes too much diffusion as well so I can't recommend unless it's for learning.
Oh, you should cover the ink curing process if you can, it affects longevity and durability especially for cloth prints.
Printer here:
A screen is usally named (mesh count per inch - single thread thickness) so a 120-34 screen has 120 "strings" per inch and each string is 34micrometers thick. That thread thickness also determines sceen thickness (twice 34) and the thicker the screen, the higher the paint-canal is, wich means more paint per mesh-opening.
On Exposure: And also regarding the paper as a medium to transfer the image...
The ink used in general printers is letting light through, even when you print twice on top of each other. If you hold a bright small light (phone flash) against your black layer printed.. you SHOULD NOT be able to see the light through. If you do, all your resolution wont help, your exposure times go up, but at the same time you lose the harsh edges. (wich you need to print clearly!) and might not even be able to wash out the screen. You want the shortest exposure possible, with the brightest light you can achieve on a private scale, with the most non-translucent black to begin with. Thats why your screen got "stubborn" Don't use pressure washers to free up the screen though. You'll lose the "pixels" that only hang onto the mesh on the edge., but they make the resolutions o much better. And dont use paper(it might let through more UV-light, but the fibers scatter the light thousands of times before letting the light escape on the other side, if at all, leading to unwanted exposures on non-image areas, leading to lower resolution. Use film. Maybe even these overhead-projector films.
The weight: Nice Idea if you have a flat lightsource that can withstand light. =)
Cheerio
To increase contrast on your print you can keep your printed sheet in solvent vapors for 10 - 20 minutes. The ink will melt and create smooth surface.
I know you were looking for image integrity being retained in the process and that is often important.
On the other hand if you don't need the output to be without loss then a hack I tried with respect to the actual screen itself gives pretty good results. Specifically I built my own frames and rather than apply commercial screen I tried 'dollar store' shear curtain material. In my experiment I wanted a painterly feel to the image. To achieve this I thinned SpeedBall's drawing fluid and painted on a floral design in a manner similar to one of my watercolor paintings. I then used SpeedBall's screen filler followed by, once dry, washing out the drawing fluid. At this point I looked through the screen and decided the edges in the image were a bit too well defined and giving more of a coloring book or poster feel to the image than the look of a painting.
I then grabbed a brush and a bottle of white inexpensive acrylic paint and brushed it into the image to break up the continuity that was giving the coloring book look to the image. I then ran a print. It was gorgeous and looked like I had painted the floral design on the paper entirely by brush. Not only did my lines and fields of color have the painterly look but the acrylic paint having only partially filled grid openings in the screen created beautiful high lights and over all a very good sense of depth was achieved in the image allowing the viewer to feel he or she was looking into three dimensional space.
Wow, I have a bag of photopolymer sheets and I never got around to figure out how to work with it. This video is the perfect starting point. Thanks!
Great video for starting on silkscreening. This pretty much sums up my 5 years experience silkscreening PCB. One thing to add. Very high resolution positive films can be obtained from imagestter. It makes a big difference for finer prints of line width of 8 mils or less.
This is exactly what I have been looking for. I love details and this hits the mark! THANK YOU
I REALLY wish you did videos more often. I learn so much from your vids.
Yes, that was very helpful. Thank you. I have always wanted to get to the bottom of how screen printing worked.
Great helpful video, I’ve been screen printing for a few months now at my job using the Nazdar epoxy ink under mil-std-130. There are also variety of lead and cadmium based inks but they are all very sticky and quite messy.. as well as fun to work with. I am mainly parts marking so printing a large assortment of surfaces.
Thank You!! This video has been very helpful, full of useful information. I can not wait to apply these techniques to my next screen printing project.
I'm a screen printer. When washing out the stencil, as soon as you get the emulsion whey, it is no longer light sensitive. After burning a screen, I would spray it with water and use my hand to spread the water over the entire image...both sides...the wash out the stencil in daylight with no issues.
:)
Daylight as the light in the room....I wouldn't try washing out in direct sunlight. Wet emulsion is seemingly less sensitive but not, not sensitive. I coat and wash out under room lights but wouldn't want sunlight streaming into the wash out area. Definitely no need to wash out in a darkroom setting. Printer since '92
Great observation on the UV transmissive properties of vellum versus transparent film, Ben. That's really helpful. Thanks a lot.
I used to work at a DVD Factory, this is how we printed the pictures on the DVDs. we would use UV lights in between each color with the ink. It would dry in literally 1 or 2 seconds for each color.
Appreciate the time you take to pass on your experience. You just filled in some gaps I had regarding uv film. Thank you very much!
Every video is something awesome that makes mego "Wow, I never thought of this but should try it!"
One of the worst things about screen printing in my 2 years of experience has been using different types of emulsion and capillary film and having to adjust the exposure times accordingly. It is really frustrating to burn out a screen, only for all your emulsion to pop out, leaving you to re-emulsify, reburn, adjust burn times, and try again (usually repeating this process a few more times until the exposure unit is set to the right time) thank you for the help!
Next Video: "10 micron high resolution DIY photolithography of ITO".
-My dreams
I am waiting for the same lol :)
NO
he can soon make cpu
You could make meta materials with that process
I Screen print all the London Bus Destination roller blinds, we use 72 mesh count and the edge detail on curves is suprizingly sharp. really small text you need finer mesh but you can get fine edges on large text on a bigger mesh count ,also provides better ink coverage/opacity. 21 years experiance. Screen printer for life :)