We've been making so many face shields here at Adafruit that we have a bunch of elastic left over and thought it would be handy for folks making PPE. Here is a 10-pack of Elastic Latex Strips, especially useful for making face shields or face masks. No 3D printing required - although you can also use these with 3D printed designs to make them fit nicely.

These are just the elastic strips, no staples or tape included. Pre-cut to 14" / 35.5cm long, and a little over 1" wide (2.75cm)

Like most sewing elastic, strips contain latex and are not recommended for those with latex allergies - just let folks using your PPE know that there is latex embedded inside.