U of S | Mailing List Archive | alt-photo-process-l | Re: Paper negatives

Re: Paper negatives

On Oct 11, 2008, at 9:06 PM, Katharine Thayer wrote:
It could be dichromate stain, or it could be a light pigment stain, depending on the pigment, or a combination. The easy way to tell is to soak it briefly in 5% potassium metabisulfte or sodium bisulfite (followed by rinsing in water) if it's dichromate stain it will come right out.
Quick clarification: What I meant here is that a warm black, like ivory black, can leave a warm stain like that in the highlights that can be indistinguishable from dichromate stain, so the only way to tell which it is, is to treat it with a clearing agent.