I keep hearing about Azo paper with Amidol being superior for contacts. I've kno wn about this stuff for years but never tried it, thinking that regular hi-quali ty paper is good for contacts. Why is it better than regular paper? If it has more latitude, I certainly would like to try it. I find it difficult t o judge the darkroom exposure time for different negatives for contact prints, u nlike enlarged negatives. Where can I get Azo, and Amidol developer? Isn't this the developer that stains your fingernails?