Discoloration

Saloni Ghuwalewala <ghuwalewala [at] vsnl__com> writes

>I have a charcoal illustration on paper...
>... and the face has discoloured to
>silver....
>... It reminds one of silver halides having come to the
>surface of a silver gelatin print.

This certainly sounds like a charcoal drawing over a photographic 
image on paper sensitized by silver bromide. In the U.S., it was 
quite common to make such drawings (or paintings) over a 
photographic enlargement.  Some of these were known as "Crayon 
portraits." To make such a portrait, a deliberately faint image 
would be enlarged onto photographic paper or even directly on 
canvas.  For a discussion of such portraits, see Stanley B. Burns, 
Forgotten Marriage: The Painted Tintype and the Decorative Frame,
1860-1910, which despite its title is not limited to tintypes.

Gary Saretzky
Saretzky Online


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                  Conservation DistList Instance 13:35
                 Distributed: Friday, December 17, 1999
                       Message Id: cdl-13-35-003
                                  ***