Re: Sistan Formula

Ryuji,

A couple weeks ago I ran some tests with VDB and various toners both
before and after fixing. Originally done to determine whether KRST
could be used a high dilution to tone VDBs without unacceptable levels
of bleaching, I also included Kodak Polytoner at two dilutions, and
Clerc's thiourea-gold toner along with untoned prints for comparison.

As you suggest, the polysufide toner (Polytoner) fogged and bleached the
prints considerably, especially when applied before fixing.

If you care to see the comparison (be forewarned it is a nude in the
woods image), you can find it at the following URL:

http://my.net-link.net/~jsmigiel/images/technical/toners/vdb_test_11.28.05.jpg

There was also a discussion in the apug.org alternative processes folder
about the same time about toning VDBs.

Joe

--
>>> rs@silvergrain.org 12/11/05 4:28 PM >>>
I currently don't have plan to start a new process.  But do you care
to share what you tried and what/how/why things failed?
I understand noble metal toning is given before fixing, while
chalcogenide (sulfide, selenide, telluride or combination thereof)
toning is given after fixing. It is probably very difficult to make
chalcogenide toners that can be used before fix, as these agents react
with silver nitrate very rapidly. So, unless someone invents a better
fixing bath, I assume that you'll have to make adjustment in exposure,
or partially tone with noble metals before fixing and then use
chalcogenide after fix to complete the archival treatment.
One obvious thing to try is to dilute KBT way further than what's
typically used for developed-out silver gelatin prints. This has an
obvious disadvantage of very unstable solution and risk of staining,
but my recent modification to chalcogeniding toner may help these
problems (besides stain caused by reaction with residual iron
compounds).
Another obvious thing to try is selenium toners. KRST may change the
image hue/density too much, but T-55 type toner might work better.
If you care to send me some test prints/rejects of otherwise
meticulously prepared and processed VDB or kallitype, I might be able
to try something along these lines, but before I promise anything I
like to know what's already tried and what's known to fail.
Also, I understand that there are zillions of variations in
iron-silver processes, but what are the current needs for improvement?
Ryuji
From: Sandy King <sanking@clemson.edu>
Subject: Re: Sistan Formula
Date: Sat, 10 Dec 2005 17:54:11 -0500
> Ryuji,
> 
> Wish you would try some of the alt processes such as vandyke and 
> kallitype and develop a sulfiding toner system for these processes. I 
> have tried myself but nothing seems to work so I keep going back to 
> gold, palladium and platinum.
> 
> Sandy
> 
> 
> 
> >From: Richard Knoppow <dickburk@ix.netcom.com>
> >Subject: Re: Sistan Formula
> >Date: Sat, 10 Dec 2005 12:55:21 -0800
> >
> >>     My understanding is that Sistan and Ag-Guard are
> >>  effective but less so than a polysulfide toner like Kodak
> >>  Brown Toner, do you agree? If so perhaps the use of the
> >>  toner is a better alternative than attempting to make a home
> >>  made version of Sistan.
> >
> >Sulfiding toners (such as polysulfide toners) are highly effective,
> >but these may be a bit difficult to use for non-developed out silver
> >based processes without severely affecting hue and tonality. Ag Guard
> >is far easier to use, and it is also a lot closer to WYSIWYG basis.
> >
> >In my experience of using various polysulfide toners, it is very
> >important to know very closely the paper emulsion, the paper
> >developer, and the toner as a combination, in order to use the toner
> >to achieve desired visual effects.
> >
> >I have recently developed a very rapid acting (at room temperature),
> >reduced odor polysulfide toner and I primarily use this toner, but it
> >still has the offensive odor and I wouldn't use it without adequate
> >ventilation.
>