Discolored paper

Marieke Kraan <kop.papierrestauratie [at] planet__nl> writes

>A few months ago, we received an piece of art (acrylic on paper) in
>our studio. The work on Fabriano paper was framed on plywood
>(Meranti) and fixed recto at the edges with water soluble tape.
>...
>The treatment was really successful. The brown colour disappeared
>and the paper kept a beautiful tone. But, after a few weeks,
>meanwhile the object again hung on the wall, there were appeared a
>million of little brown spots (like copper corrosion) in the edges.
>It doesn't look like foxing, the spots are not as light as foxing,
>but dark red brown. There are also yellowish stripes at some places.

I would have thought the starting point was to find out more about
the paper. Fabriano make a huge range with variety of raw materials,
sizes and chemical additives. If you contact them with as much
description of paper, date (if known) and watermarks they may be
able to assist. On the face of it the discoloration could be due to
light since the tape and paint have prevented it. However maybe it
is due to exposure to the air except where protected.

The millions of spots could be due to the original discoloration
reappearing or maybe your treatment has reacted with something in
the paper that has not washed out and started a different
discoloration process.

I assume that you have eliminated the possibility of there being
some sort of particulate contamination of your water, either
chemical or biological (e.g. fungi)?

Simon Barcham Green


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                  Conservation DistList Instance 17:17
                  Distributed: Thursday, July 31, 2003
                       Message Id: cdl-17-17-005
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