Thanks, Ron. I may do some tests. Of particular interest is some 11x14" EPR that I have that's circa 1992 and has been going magenta. Some of it in opened packages has faded around the edges, so I would consider that unusable, but some is still sealed, so if it's gone magenta in an uniform way and might be bleached back to normal, it would be worth running some tests, 11x14" color transparency film being a costly proposition.