Barbara,
To begin with, there should be no problems encapsulating parchment,
provided the conditions of display and subsequent storage are appropriate.

Conditions within a frame (i.e., under glass) or encapsulation are not
the same as conditions within a room.  In a room, if the temperature goes
up the relative humidity goes down; in a frame/encapsulation, the
opposite happens, because moisture may be cooked out of an artifact by
heat, and light/lighting provide a source of heat.  Worst case scenario
is that when the lights are turned off (or the blind are closed, etc.)
moisture may condense inside the frame/encapsulation to be re-absorbed by
the artifact, causing dimensional change.

Parchment is more sensitive to changes in moisture content than many
other kinds of artifact.

I would suggest that you find a conservator in your area who has
experience with parchment and ask them to examine your documents and
advise you.

Jack C. Thompson
Thompson Conservation Lab
Portland, OR
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On Fri, 19 Jan 1996, Barbara Ware (ANT) wrote:

> I hope that someone out there can help.  We are a small museum with
> volunteers who try very hard to do things correctly. We are
> mounting an exhibit which has some very old parchment documents.  We want
> to encapsulate them in acid free mylar, and are wondering how to take
> care of these documents both during the exhibit and afterwards.
>
> _________________________________________________________________________
> Barbara Ware
> University of South Florida
> Anthropology
> email:  [log in to unmask]
>