Quote Originally Posted by dpurdy View Post
I decided to just use 1/4" plate glass, two sheets. I found I needed clamps to really get it tight. The glass was 11x14.
Then I started printing on 11x14 paper and needed oversized glass. I tried So I got glass cut 14x18 and started using 8 small size industrial clamps. 3 on each side and 1 on each end. Now I get tight registration. I have never seen any newton rings.
Will insufficient pressure from the glass on the negative and paper cause Newton rings? I am going to take a shot at 20 x 24 inch contact prints, and I want to be sure that I set up in such a way that I do not have a problem with Newton rings. It appears from your post that anti Newton ring glass is unnecessary. In fact, it seems to me that I have read posts from individuals that encounter problems with Newton rings in making enlargements despite their investments in anti Newton glass.