Deterioration within enclosures

I'm sure the explanation for accelerated deterioration of framed paper
at the voids in wooden (or presumably other) backings is more
complicated than my speculation, but you did leave one obvious
phenomenon out of your equations -- paper is more exposed to moisture
migration at the voids, where the paper of the work is not "buffered"
(in the sense of a mitigating factor) by the volume of the wood.  You
would expect this to be especially severe in a framed object hung on an
outside wall.  Wooden backings probably even out the contribution of
atmospheric moisture to deterioration in the overall sheet.  An
empirical demonstration of the dangers of humidity?

Karen Motylewski
Northeast Document Conservation Center

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                  Conservation DistList Instance 6:52
                  Distributed: Sunday, March 28, 1993
                        Message Id: cdl-6-52-001
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