Re: Clearing of Iron Salts in Pt/Pd paper (fwd)

Sil Horwitz (silh@iag.net)
Thu, 13 Nov 1997 22:47:24 -0500

At 05:29 PM 1997/11/13 -0800, Beakman wrote:

>Cheaper? Possibly. More effective? I have yet to see it. And yes, it is
>true that HCA was not made for clearing platinum prints, but neither was
>citric acid, sodium sulfite, hydrochloric acid or any of the other
>effective tools. Unlike the others, HCA was however formulated to be a
>clearing agent.

Very poor terminology. It is not truly a "clearing agent"; it is a wash aid
which works on the gelatin to open it up so the hypo is easier to wash out.
Surfactants (detergents) can be used for this purpose also, and some of the
proprietary solutions are a combination of both. As the stuff was
compounded specifically for gelatine films and prints, there are probably
(undoubtedly) other materials (noted in some other msgs) which are much
better for alternative prints. (I have to restrain myself from going into a
very technical dissertation on this, as I think enough has been said.) The
true answer is experimentation, no matter the reason, if something works
the way you want it to, that's the right way to do it!

Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@iag.net
Visit http://www.psa-photo.org/