Berol Prismacolor art pencil for labeling photographs

The Photograph Librarian has recently heard of people using Berol
Prismacolor Art Pencils to label the backs of resin-coated photographs.
Specifically, Copenhagen blue was used and it does write well but we
would like information concerning the long term effects on the photos.
can anyone help?

Artemis BonaDea
Conservation Technician
Alaska State Library
Box 110571
Juneau, AK  99811
907-465-2924
Fax: 907/465-2990

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                  Conservation DistList Instance 8:63
                 Distributed: Sunday, February 12, 1995
                        Message Id: cdl-8-63-014
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