From: Sil Horwitz (silh@earthlink.net)
Date: 08/31/00-10:07:11 AM Z
At 2000/08/31 08:47 AM -0400, Joachim wrote:
>I had also tried contrast reduction for litho with Farmer's diluted and
>found results so erratic that I abandoned it.
Farmer's is ferricyanide plus hypo - won't work properly. The plain
ferricyanide is a weak bleach only, while Farmer's will actually etch out
some of the image (in the highlights of a print, unfortunately not what you
want it to do). When you use the dilute ferricyanide, it changes the
molecular structure of the undeveloped silver. I don't know the exact
structure, but it is definitely not a bleach like Farmer's, which is a
combination with hypo.
Sil Horwitz, FPSA
Technical Editor, PSA Journal
teched@psa-photo.org
silh@earthlink.net
Visit http://www.psa-photo.org/
Personal page: http://home.earthlink.net/~silh/
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