Re: archivalness of gum
Thanks for that link, John. I love Malin's site, but certainly
missed this (having spent most of my time just looking at the
pictures). ;)
Diana
On Dec 21, 2007, at 7:43 AM, john@johnbrewerphotography.com wrote:
Hi Diana
An article on the ghosting of platinum can be found on Malin's site
here: http://www.alternativephotography.com/articles/art063.html
Best
John.
www.johnbrewerphotography.com
----- Original Message ----- From: "Diana Bloomfield"
<dhbloomfield@bellsouth.net>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, December 21, 2007 3:53 AM
Subject: Re: archivalness of gum
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.
Diana
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???
Chris
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.
--
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