when to bleachgreenspun.com : LUSENET : B&W Photo - Printing & Finishing : One Thread
I would like to spot bleach on a dry print. The ones that I have done do not seem to be effected by the bleach. But maybe I am using the wrong strength. I have been using Tim Rudman's technique of fixing, washing, selenium toning, hypo, washing. Therefore the bleaching was done after the print dried. I thought it was prudent to observe the dry print to see if bleaching would even be necessary. Does the toning before bleaching reduce and/or eliminate the effect of bleaching? Any thoughts appreciated. thanks carol
-- carol maurin (email@example.com), November 10, 2000
Selenium toning will render normal ferricyanide bleach ineffective or unpredictable in use. The bleaching should be done before the toning, but the prints will need a very thorough wash before toning. There may be a bleach that's effective on toned prints. Perhaps acid/Dichromate? I don't know, I've never tried bleaching toned prints.
-- Pete Andrews (firstname.lastname@example.org), November 10, 2000.
Right! The selenium protects the silver and prevents bleaching.
-- Ed Buffaloe (email@example.com), November 10, 2000.
The selenium resists bleaches effectively so all bleaching should be done before the toning stage. Strong bleaches can be used after Selenium to induce colour change, but do this not by bleaching the selenium but by bleaching the silver 'grains' which have not been converted to silver selenide as they are darker/colder in colour and mask the selenium colour to a degree. Removing them reveals the redder silver selenide more clearly. (I read this in one of Tim's recent articles on toning) However, you wouldn't want to do this for spot bleaching Harry
-- Harry Sullivan (firstname.lastname@example.org), November 11, 2000.