Re: archivalness of gum
An article on the ghosting of platinum can be found on Malin's site here:
----- Original Message -----
From: "Diana Bloomfield" <email@example.com>
Sent: Friday, December 21, 2007 3:53 AM
Subject: Re: archivalness of gum
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
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
believe it was fairly well known... Then again there were many kinds
"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.
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