[pure-silver] Re: Old Paper Developer Question
----- Original Message ----- From: "Don Sweet" <don@xxxxxxxxxxxxxxxx> 
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Sunday, February 17, 2008 9:13 PM
Subject: [pure-silver] Old Paper Developer Question
I have few boxes of 25+ year old enlarging paper, including Ilfobrom and Portriga Rapid. It is unopened, so I decided before blazing away I should look for some information about how to best to process it, particularly to minimise fog. First I sourced some benzotriazole which I thought could just be added to Dektol or Neutol or Bromophen developer.
Then following links from the UnblinkingEye website I found some suggestions that both amidol-based or glycin-based developers are more resistant to fog than the usual MQ or PQ blends. Does anyone know if that is right, and whether either of them is likely to be a better developer for my old paper? 

Thanks
Don Sweet
The fog in old paper or film comes from a chemical change in the emulsion. I think the advice about Glycin or Amidol may come from some confusion about the type of fog here. Some developers are less likely to cause fog themselves than others and don't need as much anti-fog. However, this is also dependant on pH. Some low activity film developers, like D-76 and D-23 don't produce enough fogging to require an antifoggant although fresh D-76 will produce a slight amount of fog. Higher pH developers of the sort usually used for print developing nearly always need some anti-foggant. This is also because fog is not tolerable in prints but can be tollerated in film if not too great. Benzotriazole is more effective in reducing fog in old paper than bromide although bromide often works. Benzotriazole also tends to produce cold images where bromide tends to warm them up. Usually benzotriazle will result in less loss of speed. Grant Haist has a chart in his book showing approximate amounts of a benzotriazole solution to add to developers for different amounts of fog. Be aware than if the fog is bad enough no anti-foggant can fix it. Also, the antifoggant will affect the paper curve a bit so it won't look quite the same. Plain Dektol or Bromophen or any other standard paper developer works fine with this stuff. Unfortunately, my copy of Haists' book is boxed up at the moment. 

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx


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