Discoloration

I have a charcoal illustration on paper of a young man belonging to
a client. It was painted by an Indian artist called Pithawalla, in
1908. Apart from the usual problem of the paper having darkened and
it being adhered to an acidic board, the face has discoloured to
silver. It appears that something was applied to highlight certain
contours of the face, that something, having changed colour to
silver. The reason I would say that it was deliberately applied, is
because no where else on his body has it occurred. Furthermore, the
silvering corresponds to highlights in the eyes, ears, etc. I have
not found any mention of this unusual occurrence in any literature I
have read. It reminds one of silver halides having come to the
surface of a silver gelatin print. There is no oily haloing effect
around the silvering either. It almost looks as if the colour itself
has been painted, which cannot be the case because no one would have
bought the painting! Does anyone know if certain fixatives changed
colour to silver over the years?

Saloni Ghuwalewala
Paper Conservator
"Vallabh Niwas" 1st floor
31-A M.L.Dahanukar Marg
Mumbai 400 026
India
+91 22 4951346

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                  Conservation DistList Instance 13:34
                 Distributed: Sunday, December 12, 1999
                       Message Id: cdl-13-34-015
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