What kind of accelerated aging test was it?
>Anna Atkin's work that I've seen from over 150 years ago is still looking
>good
I routinely see 100 year old cyanotypes in very good to excellent condition.
>Of course cyanotypes need to be kept away from alkalis. They are I think
>stable to acidic substances that are more often a problem (for example in the
>breakdown of some papers and in atmoshjperic pollution.)
...
>Gold toned (or platinum toned) salt and albumen prints may well have similar
>life expectancy to other toned silver processes, but the storage conditions
>are important here. The main problem I've had personally with silver gelatin
>prints is mould growth on the gelatin. I'm told this may be a sign that I've
>washed out the fixer too well, as well as of the dampness of my home.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Washing out the fixer too well causes mould growth? Never heard tell of
that! I would blame it on dampness. Kodak and others used to have
publications for processing in damp climates. One solution would be to keep
your collection in one area where you can have a small but effective
dehumidifier running through the damp period of the year.
>Platinum and carbon are generally though to be pretty permanent - though I
>suppose you could do carbon with impermanent pigments if you wanted to. Some
I just had to work on a family album that had a dozen Pt prints and maybe a
hundred silver prints, made ca. 1890 -1910. All the silver prints were
faded, some quite badly. Most Pt prints had a fair amount of reddish stain
in the highlights but the quality of the work was quite amateurish at best
so there is a good chance that little attention was ever paid to good
quality processing in the first place.
This said, old carbons tend to remain in remarkable shape compared to
everything else that's ever been used. Part of the reason being, I presume,
that the process has always been more difficult than most others and
therefore reserved for high quality work.
Of course, you are more likely to have mould problems with carbon than with
Pt since carbon images are held in a layer of gelatin.
Luis Nadeau
NADEAUL@NBNET.NB.CA
Fredericton, New Brunswick, Canada