Mylar and storage

I'm wanting to know what the current thinking is about storage of
artwork in mylar.  I know about the obvious - no pastel, no chalk, etc.,
but I wonder if newer studies have lengthened the list of "friable
media" or if there are opinions on gouache, watercolor, pencil and other
media.

Sandra Markham
Beinecke Library, Yale University

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                  Conservation DistList Instance 6:54
                 Distributed: Thursday, April 15, 1993
                        Message Id: cdl-6-54-006
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