Why 3D Printers LOVE Triangles - The Story of the STL File

In the 1980s, Chuck Hull was working at Ultra Violet Products, where they used UV lamps to cure plastic coatings on tabletops. But when he needed a custom plastic part for a lamp he was designing, he faced a major problem-traditional injection molding took weeks or even months just to get one part.
That’s when he had a breakthrough idea: What if UV light could be used to create a 3D object, layer by layer? 💡
This idea led to stereolithography (SLA), the first 3D printing process, and the birth of 3D Systems-the first 3D printing company.
But there was another challenge…
💾 Standard CAD files were too complex for 3D printers to process.
So, Chuck Hull invented the STL file format-a genius solution that simplified complex 3D models into thousands of tiny triangles, making them easy for 3D printers to understand.
🚀 Why do 3D printers use triangles?
Triangles are the simplest shape that can represent any 3D surface.
Unlike quads or N-gons, triangles never warp in 3D space.
STL files make slicing and printing fast and efficient.
From a simple UV lamp to a worldwide 3D printing revolution, Chuck Hull’s STL format is still the industry standard today.
🔔 Subscribe for more 3D printing history, innovations, and tutorials! 🔔