Re: archivalness of gum
Title: Re: archivalness of gum
Diana,
Metals are classified by a scale known as the galvanic series,
which determines the nobility of metals and other substances such as
graphite (graphite is actually a polymorph, as is a diamond, of the
element carbon). According to the galvanic series, the order is 1)
graphite, 2) palladium, 3) platinum, 4) gold, 5) silver, 6)titanium
and so on to the stainless steels and bronzes.
So it is true that platinum is more stable than gold, but
palladium is more stable than platinum, and carbon is more stable than
palladium, platinum and gold.
Many people have observed that when a platinum print remains in
contact for a long period with covering piece of paper there may be a
partial transfer of the image from the original print to the other
paper. To my knowledge this has not been observed with gum or carbon
prints.
Sandy
At 2:14 PM -0500 12/20/07, Diana Bloomfield wrote:
Well, I was told at one time that
platinum is more stable than gold-- consequently, at least one of the
reasons it's the most archival. (The other reason is probably
that it's so ridiculously expensive that we have to convince ourselves
that it has to be the most archival, if not the most beautiful, in
order to justify the cost.) Whatever-- I'm thinking
I'll still go with the platinum-is-more-stable-than-gold story
whenever some museum curator asks me that question-- that is, until I
learn carbon printing, or perfect gum printing. :)
Diana
On Dec 20, 2007, at 1:27 PM, Sandy King
wrote:
Diana,
In fact gum (and carbon also) are
probably more permanent than platinum, assuming one uses light fast
pigments. Carbon pigment is totally inert, and a print that consists
of carbon pigment in a hardened layer of gum arabic or gelatin would
be limited in terms of life more by the support on which the print is
placed than the image itself.
Sandy King
At 12:03 PM -0500 12/20/07, Diana
Bloomfield wrote:
Hey Chris-- Isn't platinum the most
archival process? At least, that's what I always tell people.
I'm sure I read that somewhere. I did have someone ask me an
interesting question recently that I never thought to ask anybody--
but I had made a gum over platinum print, and this person suggested
that by using gum over the platinum, I was harming the platinum in
some way-- or, at least, somehow removing the archival nature of the
platinum, since-- this person said-- gum isn't archival. I think
this person was only *assuming* that gum isn't archival-- really
didn't know for sure-- but I thought it was an interesting
question.
On Dec 20, 2007, at 10:30 AM, Christina
Z. Anderson wrote:
Good morning
all!
This may be
a question for Gawain Weaver as I don't know who else on the list is
"in the know".
I have
always read/thought/been told that gum along with carbon is the most
archival process there is.
I heard a
comment the other day from a museum curator who said it was "not
the most archival process".
Now, I know
that certain pigments used in the past were NOT lightfast.
Gamboge, alizarin crimson, etc. were pigments that faded thru time we
now know and the watercolor painters know, too. Also, I know
that if you leave the dichromate stain in as a darker brown addition
underneath the gum layer, through time in sunlight that image will
fade to gossamer green and therefore the print will lighten
**somewhat** (found a cute little article on that fact about gum
prints "fading on the walls of exhibitions"). But if
using archival pigments and also taking into account the slight tone
difference of an added dichromate stain now that we are not cooking
our prints with heavy 100% sodium dichromates, etc.,, aren't gum
prints really archival?? Anyone have gum prints that have not
lasted? I've seen Kuehn's and Demachy's but unfortunately,
photography is a relatively new art and thus we only have about 170
years of evidence.
Unfortunately, I left my only conservation book (thanks,
Gawain) at home and I am in FL for 3 wk--writing my gum book at
least!
Chris
Christina Z.
Anderson
Assistant Professor
Photo Option Coordinator
Montana State University
Box 173350
Bozeman, MT 59717
406.994.6219
CZAphotography.com
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