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
On Dec 20, 2007, at 7:53 PM, Diana Bloomfield wrote:
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?
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
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
believe it was fairly well known... Then again there were many
"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
but ... as noted, this memory is not archival.