> I have been under the impression that the Kallitype's reputation for
> fading and discoloration was undeserved and that the culprit was improper
> processing, i.e. incomplete removal of the iron salts. The finely divided
> silver of the image is much more sensitive to this problem than platinum
> in the platinotype. Am I wrong? I base this on the Thomas A. Wynne paper,
> _The Kallitype_ from Spring, 1982. I believe this paper was distributed
> some years ago by Light Impressions. Maybe it still is.
>
> Claude Seymour
I don't have my copy of Crawford handy but I think he says the original
kallitype formula which gave it is poor reputation was deficient: it
called for ammonia instead of hypo as a fixer. But the Wynne paper sounds
right too: residual iron is a problem, and its hard to remove because of
the use of a highly alkaline developer, which you have to use or else the
image simply dissolves away. There's a brief explanation of this in Ware's
article: he set out to overcome these fundamental weaknesses with his
argyrotype process.
Philip Jackson