[pure-silver] Re: "archival pigment print"
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sat, 20 Feb 2010 12:44:25 -0800
----- Original Message -----
From: "Shannon Stoney" <shannonstoney@xxxxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Friday, February 19, 2010 12:36 PM
Subject: [pure-silver] "archival pigment print"
I went to a photo show today in Houston, and about half the
prints were "archival pigment prints." This was at a
prestigious gallery in Houston, and the prints were up for
auction. There were some gelatin silver prints too, and
some chromogenic prints, and a few alt process prints.
it's nice that there's such a variety of different kinds
of prints now. The "archival pigment prints" were mostly
very sharp and good. But, why do only *they* get to call
themselves "archival"? Aren't silver prints "archival"
too? This term--archival pigment print--makes ink jet
prints sound somehow better than "regular" prints. I
wonder if they really are. Can an inkjet print (which is
a more honest description) really last a hundred and fifty
years like a silver print?
I think I am going to start calling my prints "archival
silver prints."
--shannon
That makes you think they are carbon prints but I'll
bet they are ink-jet prints made with so called archival ink
sets. If the gallery has no other description I think they
are being seriously dishonest.
Some ink sets claim very long life, in excess of 100
years. Generally "archival" which has no formal definition,
means an expected lifetime of 100+ years. While there is a
track record for silver-gelatin and some "alternative"
prints, mostly carbon or platinum, there is absolutely none
for computer prints. The life expectancy has been determined
by accelerated aging tests which may or may not be valid.
Silver-gelatin prints can be "archival" and there are
plenty around which are over 100 years old, many of which
did not receive any special handling in processing.
In general the effects which tend to limit the life of
silver-gelatin prints come from chemical decomposition of
the silver image and of residual chemicals in the emulsion
or support. The most common cause is apparently from
incomplete fixing but poor washing is a close second. As it
turns out what was considered "archival" washing in the past
may have shortened the life of the pictures so processed. It
was discovered by T.H.James of Kodak, around 1960, that a
very small residue of hypo in the emulsion acted as a
stablizer to some degree preventing oxidation of the silver
image. This effect is nowhere near as effective as proper
toning but there are a lot of snapshots processed by
photofinishers which are still in perfect condition at least
partly because they received no more than routine washing.
Inadequate fixing is something else because it results
in an overall stain and eventual sulfiding or fading of the
image.
Any sulfiding toner or selenium toner will yield very
permanent images when toning is carried out to completion.
However, Kodak Rapid Selenium Toner, which was the standard
treatment for microfilm for years, was found to be
ineffective at the high dilutions (1:19) being used. This
was found in research carried out by the Image Permanence
Institute of the Rochester Institute of Technology. The
currently recommended treatment for microfilm is toning in a
polysulfide toner, like Kodak Brown Toner, to the point
where sixty per cent of the image silver is converted to
silver sulfide. For prints toning to the point where there
is a visible change in image color or density is probably
enough. KRST does work but prints or negatives must be toned
further than in the old recomendations. Dr. Douglas
Nishimura, of IPI, told me that KRST is effective but must
be used at a dilution of not more than 1:9 and for not less
than 3 minutes at that dilution. This is not acceptable for
microfilm because it changes the image structure too much
but is fine for prints.
The other standard treatment for microfilm, which is
also applicable to pictorial negatives and prints, is gold
toning. Gold, like selenium has minimal effect on image
structure, color and density but does have some. Most papers
tone either neutral or blue in gold toners. Generally warm
tone papers will tone to a stronger blue color but mostly it
is a cooling of the print. The only drawback to gold toners
is the cost. Prints toned in gold will turn brick red if
subsequently toned in a sulfiding toner and can be used to
produce interesting split-toned images.
If you can get back to this gallery I think it would be
interesting to pin the gallery owner down about just what is
meant by "archival pigment prints" and make it clear that
they are on the dangerous edge of fraud with such a vague
and potentially misleading description.
--
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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