How to make a face mask with elastic fits for the ears

To make these face masks you need:
Poplin fabric made of cotton and polyester can be solid or printed
Cotton fabric for sheets from 300 to 400 threads, the more threads the more protection. A test that you can do is to place a piece of cloth well glued to your lips and blow, a greater resistance of exit of your seat better protection will give you.
1 rectangle of each fabric of 18 x 24 centimeters
1 nose bridge adapter (you can find them on e-Bay, Amazon or Aliexpress)
2 pieces of 25 centimeters each of soft elastic cord