Re: archivalness of gum
Judy, Gawain,Diane, etc.
Diane--platinum ghosts onto paper it is in contact with so it loses some of its precious metal in storage I remember Dusan Stulik telling us/showing us at an APIS. In fact, this is a method to determine whether a print is a platinum one or not.
I was always under the assumption that carbon and gum were THE most archival of all processes. That is why this curator's comment surprised me so much. I have yet to come across any discussion of degradation of gum prints except for the one article talking about the fading of the dichromate image within the gum print. This can be easily demoed by leaving a gum print in the sun for an afternoon, half covered by something for comparison's sake.
Judy, gum over platinum has been done since 1902, invented by Herbert Silberer, an Austrian.
Holland Day did it as did quite a few other Americans, and I have never heard that wasn't archival either. In fact, one author said the French were known for one coat gums, the Germans for multiple coat gums, and the Americans for gum over platinum.
Gawain, I have seen some original Kuhn's at A Gallery of Fine Photography that were perfect, and just hanging on the walls there like no big deal. He was a master printer of the multiple gum, as was Demachy...but the bug thing has got to be an issue and I wonder if use of formaldehyde for hardening gelatin gives the benefit of preserving it from bugs...oh, the cracking in the dark thing...I wonder if sizing would contribute to that phenomenon?
So what I have deduced, after this discussion to date, is gum is what I think it is and I wasn't whistling Dixie. I wonder if Wilhelm has studied gum stability???
And also, by the way, gum over platinum is an historic process -- if