Re: Eastern European RC papers

Although your suggestions are good ones, I think the real problem is
somewhat blurred. Lack of gelatin overcoat and insufficient gelatin
hardening may be seen as a problem by some users (such as students who
don't handle RC prints carefully) but I don't think they are closely
related to archival property given proper handling.

For example, I've been making enlarging and contact printing emulsion
with no protective layer for some years but with careful handling I
have not seen a problem.

This kind of image deterioration involves redox reactions. RC paper
has a generator for a strong oxidizing agent in the polyethylene
layer, for which companies in the west spent considerable effort (and
many mistakes) in 1970s, 80s and early 90s. Manufacturers like Ilford
and Kodak told users that the image deterioration was caused by poor
processing and washing, and the problem does not lie in their
products, while they secretly improved the formulation of the resin
coat. And every time Kodak said there was no more problem with their
RC papers, a new problem was found.

But putting too much focus on the RC is also very misleading in my
view, because simply using baryta paper does not ensure good
permanence. The most effective way to prevent such deterioration,
regardless of RC or FB, is to (1) treat the print in a sulfide toner,
AND (2) store prints in a dry place. Residual thiosulfate is often
blamed, but if the RH is kept low during storage, a small amount
(still several times higher than ANSI limits) of residual thiosulfate
is harmless.

From: fb <aikus2@freestart.hu>
Subject: Re: Eastern European RC papers
Date: Mon, 23 Jan 2006 11:37:13 +0100

> Loris,
>
> as I wrote earlier the RC/PE papers has more risk
> about silver degradation because soft gelatine layer
> and the missing extra protective gel. layer. The high
> density parts are most effective about the symptoms
> of the deterioration because the large amount of the
> silver. More in the case a multigrade paper that has a
> multi silvered layer from higher speed (larger) silver
> grains.
>
> The fresh fixer and normal wash is not enough usually
> to make a durable copy on RC (anyway the RC not the
> best material for a long term unchanged print).
>
> To get a good result by washing the water temp. need
> to be higher than 20 C grade while the normal tap
> water temp. usually lower.
>
> My suggestion: try to use some fixer/hypo killer before
> endwash (the simplest 10 % sodium sulphite solution
> but I think still there are some factory products also).
> Some toner (sulphur, selenium, gold, etc.) and a
> gelatine hardening bath can be good too.
>
> However the silver problems can be started because
> storage conditions also (high temp., high RH, oxidous
> gases in the air, high light/UV/IR radiation, etc.)
>
> Bálint Flesch
>
> http://archfoto.atspace.com/english.html
>
>
> Date sent: Sun, 22 Jan 2006 01:41:13 +0200
> From: Loris Medici <mail@loris.medici.name>
> Subject: Eastern European RC papers
> To: alt-photo-process-l@sask.usask.ca
> Send reply to: alt-photo-process-l@sask.usask.ca
>
> >
> > Let me share a recent experience with Forte RC papers:
> >
> > Some workprints I've made on cold tone Forte polygrade RC paper showed
> > silver plating (metallic / reflective silver particles in the dark tones) in
> > a relatively short time period (in about 6 months, regardless the place I've
> > kept them. I don't know if the papers are from the same batch). I always pay
> > extreme attention to use fresh fixer and to wash enough. This recent
> > incident was very frustating as one of the problem prints was a gift to a
> > friend - I printed the same image using Ziatype and gave it to my friend.
> > Now I'm pretty sure that it won't cause any problems. :)
>
Received on Mon Jan 23 13:24:03 2006