Monitoring for shifts in color and transparency

I am investigating how to monitor transparent and translucent art
objects for subtle and gradual changes in color and transparency. I
would appreciate hearing from anyone who knows of methods now in use
to monitor objects made of polymeric resins, glass, etc., for such
changes.

Jean D. Portell
Jean D. Portell, Inc.
(sculpture conservation)
13 Garden Place
Brooklyn, NY 11201
USA
Fax: 718-643-8773

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                  Conservation DistList Instance 12:28
               Distributed: Thursday, September 17, 1998
                       Message Id: cdl-12-28-007
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