This sheet of plastic acts as a weight for your acetate transparency while using the sun to develop your photo emulsioned screen. It's also handy for sun printing with Inkodye or SolarFast. Clip together your fabric, acetate sheet / inkjet film or 2D objects, and the plastic glass and set out in the sun using the exposure times appropriate for each product.
This plastic is not high heat resistant and should not be used under high heat lamps or run through industrial driers. Using under the sun is just fine - as long as it's used under the sun while on Earth.
It is also useful, instead of glass that might break, as a surface to put inks and paints on when using brayers to apply inks and paints to printing blocks.
Made in: FRANCE (FR)