go to the Consdistlist archives--you can get to this at the bottom of the CoOL opening page. look under search by author, and find Nimishura's post--there are several that deal with this topic, but they're hidden in other postings...I did a quickie search & found it in 9/21/97 "processing RC papers"...if you go to the Abbey Newsletter--look at Vol. 12 no. 5/ june 1988. "Stability of B&W Photographic Images with special Reference to Microfilm". Somewhere on the Distlist is another version of this same tech paper, I used to get this list at work but email got all fouled up & I lost track of it....I think the state archives nearby uses a methylene blue dye test for residual fix. You can find about these tests on CoOL as well. You probably wonder why all this is about microfilm, but that's what most of these archives use for longterm records storage and it's sorta the standard that other materials are put up against. At any rate, these are worth reading, but probably won't change the way alot of people process...