Painting installed on marble wall

We are thinking of hanging a framed painting (oil on canvas) on a
marble panel. The marble slab is an outside wall (i.e. the wall
consists of a single slab of marble, one surface of it on the
outside of the building, the other on the inside). In winter the
marble is much colder to the touch than is the ordinary wall and is,
I believe, somewhat hygroscopic, so humidity fluctuations are
probably much greater in its immediate vicinity. I am concerned
about the effect on the painting of both the fluctuations and the
difference between the temperature and humidity on its back and its
front. Are my concerns justified? Would some sort of barrier between
the marble and the back of the painting provide enough protection?

Carol Clausen
National Library of Medicine
Bethesda, Maryland

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                  Conservation DistList Instance 11:47
                Distributed: Tuesday, November 25, 1997
                       Message Id: cdl-11-47-014
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