Support material for bronze

I am looking for suitable supporting material by restoration of very
thin and weak archaeological bronze sheet. It should be rigid for
firm supporting, transparent to allow the below side to be seen and
very thin not to disturb the overall appearance of the object. The
bronze sheet is not flat so the supporting material has to be shaped
easily after it. The Plexiglas is one of the possible materials, but
it does not fit well to unevenness of the bronze sheet. Did somebody
have similar problems and can give me usable advice?

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                  Conservation DistList Instance 11:15
                  Distributed: Friday, August 8, 1997
                       Message Id: cdl-11-15-006
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