Re: When to tone?

From: Sandy King <sanking@clemson.edu>
Subject: Re: When to tone?
Date: Wed, 12 Nov 2003 09:43:12 -0500

> In case anyone is interested my question is a continuation of the
> thread on silver metal replacement with noble metal toning. One I had
> carried out the bleaching tests on palladium toned kallitype prints
> and discovered that a very small percentage of the silver metal was
> left unprotected the next logical step was to see if a second toning
> with gold, selenium or polysulfide would result in the conversion of
> the remaining silver metal to more protected substances.

General comment: It's hard for me to predict how stable the material
is in your preparation based on my knowledge of silver. This is
because gelatin in silver gelatin system provides significant
resistance against environmental pollutants in practical storage
conditions. (That's at least partly why some early silver gelatin
materials are well preserved compared to earlier silver processes
including kallitype) So what you are trying to do may sound like an
overkill to average silver gelatin people, but I think it's worth
pursuing.

In the case of silver gelatin prints, film and microfilm, even a
partial conversion of silver to silver sulfide is known to increase
stability considerably. Indeed, a bit of potassium iodide added to
fixer was commonly used to increase the permanence of microfilm though
it may not convert anything. (Microfilm emulsion is similar to
enlarging paper emulsion and more vulnerable than film/plate
emulsions.) These results do not immediately carry to your
preparation. When you consult silver gelatin literature, and say you
obtain a comparable resistance based on bleach test or peroxide
immersion test, it's safer to assume your material is less stable than
silver gelatin in real life test because of lack of gelatin.

> Regarding split toning, when one tones kallitype first with gold,
> then follows with palladium and platinum, some highly interesting
> results are possible, with purplish/bluish highlights and warm brown
> shadows.

I'm not familiar with the results of palladium or platinum toning in
SG but gold-selenium is a popular combination for double toning in SG
resulting in bluish highlights and brown black shadows, as you said.

From: Sandy King <sanking@clemson.edu>
Subject: Re: When to tone?
Date: Thu, 13 Nov 2003 00:13:25 -0500

> Are any of these papers available on the web?

I don't think so.

The IPI report is available in bound form from IPI for $50 or so. I
asked my local library to buy it.

Others are journal papers... my local library have them in their
collection.

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)