U of S | Mailing List Archive | alt-photo-process-l | Re: archivalness of gum

Re: archivalness of gum

If you faced a charcoal or graphite drawing with a piece of paper, a small amount of the charcoal would come off onto the facing paper too, but that wouldn't make the charcoal any less archival in and of itself, it just means you want to be sure to frame it so that it doesn't rub off on anything. I'm not sure I understand why the fact that a small portion of the metal that comprises a platinum print could rub off on something else detracts from its archivality. Is it likely to lose enough metal from the surface to actually degrade the image?


On Dec 20, 2007, at 7:53 PM, Diana Bloomfield wrote:

Hey Chris,

Well, that's where you and I differ (the belief that carbon and gum is the most archival-- instead of platinum). :) Honestly, today is the first time I've ever heard the news that platinum isn't the most archival. That said, the "ghosting" that you and Sandy both mentioned-- I'm curious-- how much time does that take to occur (a week? decades?), and under what type of circumstances, or does that not matter? I'm also curious -- did your curator mention what he/she believed to be the most archival?

Thanks, Chris.


On Dec 20, 2007, at 10:26 PM, Christina Z. Anderson wrote:

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
memory serves (which I can't promise, MEMORY is NOT archival) Paul
Anderson (heh heh) did it, but also I think Heinrich Kuhn, among others. I
believe it was fairly well known... Then again there were many kinds of
"platinum" including a commercial "platinum paper" -- who was the
Englishman who swore he'd stop photographing when that paper was
discontinued? He had the same name as a photo historian or other pioneer,
but ... as noted, this memory is not archival.