Quote Originally Posted by revaz_kv View Post
Thanks for info!

So I will use regular glass
Regarding the thickness, 2 mm sounds good, although I am probably going to use something thicker and thus heavier
You say heavier. Is that because you think weight will add more pressure? The pressure comes from the springs (usually three) on the back of a contact frame or the suction of a vacuum frame.

If you contact print often or all the time there is wear and tear on the glass. Once or twice a year I replace the window grade glass in my contact print frame. Scratches, pin holes and other such damage are just a part of the work for me. It happens. These of course show on the print. I keep two spare glass pieces wrapped in paper in case I need a replacement suddenly, such as breaking it or scratching it. If glass is so easily damaged that is another good reason not to use plastic.

John Powers