PET film/sheets are widely used for thermoforming, printing, folding box, die cutting, etc. 

It's high glossy, without spots  waves. It's also eco-friendly  recyclable.

 
It also can be special treated, such as anti static, cold resistant, anti UV, metallized, etc. 

Especially, it can be anti fog, it's most popular material for face shield,  it's also can be laminated with protective film.