Polyvinyl acetate

We are creating long-term storage for 2 fragile, curved glass,
hand-tinted portrait photographs.  We want to construct the supports
using PVA (polyvinyl acetate) glue, but are concerned about the
off-gassing and long term effects of it on the photographic materials.
We are uncertain of the type of photographic emulsion, but believe the
clothing styles date the photos between 1890 and 1910.  Has anyone
studied the effect of PVA on early photographic print/negative storage,
or is anyone aware of documentation to that effect? Can anyone recommend
an alternative?  Thank you for any help!

William Hopkins

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                  Conservation DistList Instance 8:50
                 Distributed: Friday, December 30, 1994
                        Message Id: cdl-8-50-006
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