I seem to remember from my college days that regular glass filters UV. What's the best glass for UV contact printing in a print frame. Is possible UV filtration the only issue one deals with in selecting a glass? Can Newton rings be a problem? I'm going to be printing with digital negatives. Gosh, I just saw a pre-existing thread ON THE SAME PAGE as my thread. I obviously missed it. Apparently, there's a Water White glass that does a good job at passing UV light. But, I don't see too much mention of whether or not Newton rings can be a problem, or how to prevent it.