U of S | Mailing List Archive | alt-photo-process-l | Re: Selenium-toning Van Dyke Brown prints

Re: Selenium-toning Van Dyke Brown prints

On Mon, 25 Sep 2006 18:23:01 -0400, "sam wang" <stwang@bellsouth.net>

> But I always wondered if it was the 
> selenium that affected the image or was it the acid - at 1:100, how 
> much selenium is there to do the toning, and so quickly?

The recipe for KRST is proprietary and I am not Eastman Kodak, so this
is nothing more than an educated guess. At 1+100, the amount of
elemental selenium is about 60mg per liter, within a factor of a few.
The solution is alkaline.

> I believe I posed the question a long time ago, "Is there another form 
> of selenium that might be used instead of KRST, and would that do 
> better as a toner for VD" and don't remember ever receiving a good 
> answer.

There is non-rapid selenium toners using sodium or potassium
selenosulfate without ammonium chloride or ammonium thiosulfate or any
of these. With silver-gelatin the toning is considerably slower than
with KRST-type toner. If you are interested in post-fixation toning of
VDB with selenium, this may be worth trying.