[alt-photo] Re: Salted paper pH

etienne garbaux photographeur at nerdshack.com
Tue Oct 11 20:49:11 GMT 2011

Joe wrote:

>Should the paper for salted paper be pH neutral, acid or alkaline during
>the process?  Alkaline buffering post-processing seems prudent, but I'm
>wondering about during salting, silvering, exposure and processing.

That depends on the particular process you use.  The paper will be 
close to neutral if you sensitize with a plain chloride bath and a 
silver nitrate bath.  However, as photographers discovered in the 
1840s, one obtains better results if the salting bath has an active 
organic component.  This is almost always acidic (commonly citric or 
tartaric acid), which will result in an acidic coating prior to 
drying and exposure.

The initial post-exposure rinse should be neutral.  Gold toners are 
alkaline, and platinum toners are acidic (I use both, gold followed 
by another rinse, then Pt).  The fixer should be alkaline, and most 
washing aids are also somewhat alkaline.

Best regards,


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