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Re : Hypo Eliminators (was: Dichromate and the plate)
Hello,
Interesting literature about wash-aids and hypo eliminators is found in the
chapter on "History of Processing and Image Stability" by George Eaton in
Pioneers of Photography, The Society of Imaging Science and Technology,
Springfield, VA, 1987.
An Eastman Kodak team of scientists has studied the adverse effects of
complete hypo elimination in silver emulsions and found that a trace of
residual hypo provides some protection against oxidation. The only case
where the use of the HE-1 solution is recommended is before gold toning
archivally processed silver prints.
Greetings.
Roger
Roger Kockaerts
Permadocument - pH7
Avenue de la Jonction 55
1190 Bruxelles
T: 32-2-3476676
You are welcome to visit our homepage at: <http://home.tvd.be/cr25588/pH7/>
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>De : Sarah Van Keuren <svk@steuber.com>
>À : alt-photo-process-l@skyway.usask.ca
>Objet : Re: Hypo Eliminators (was: Dichromate and the plate)
>Date : Mer 29 mars 2000 5:45
>
> On Sunday, March 26 Sil Horwitz wrote:
>> Don't confuse "Hypo Eliminators" with "Wash Accellerators." Kodak now
>> specifically proscribes the HE series, noting they are harmful for
>> long-term storage of prints. Wash Accellerators are buffered and are only
>> very slightly alkaline. They are aids to washing; HE solutions actually
>> destroy hypo, and just incidentally, adversely affect gelatin. I'd keep
>> away from them, including that horrible example of "caustic soda" (sodium
>> hydroxide) which can do only harm.
>
> My partner Harry Kalish wonders the following: If HE-1 was used about 10
> years ago in the washing process using the old Portriga Rapid pqper, what
> problems would one expect to see with the gelatin? Would there be changes in
> the print color over time?
>
>
> Thanks for any help you can give,
> Sarah Van Keuren
>>
>