At EK, experiments were undertaken by Grant Haist and others, to stabilize film. Among those chemicals useful, as I noted earlier on APUG, were organic chemicals with an -SH group in them or something of that sort. PMT (Phenyl Mercapto Tetrazole) comes to mind as does o-Thio Benzoic Acid, an analog of Salicilic Acid. These were used in the RA stabilized B&W papers.
PE
PE