Just a small note on the color of paint materials we are using for patching. If the material is on the inside of the bellows or camera, some place where it could reflect light on to the film, black is good. On the outside, believe it or not, white is better for blocking light. Dark colors do not contain opacifiers, where light colors do, the primary one being titanium dioxide. Nobody wants big white blotches on their bellows, of course, so some of what we are doing is about looks, but if you're looking to block light, use white paint, not black.