Displaying ephemera

This posting is on behalf of judi.browes [at] coventry__gov__uk.

    I am working on an exhibition which involves mounting a large
    number of small pieces of ephemera in such a way that they can
    be attached to the back of a showcase. Previously this has been
    done by attaching the pieces to a card backing using melinex
    strips. However, on removing some items from a permanent display
    it was observed that there was a general yellowing  of the
    exposed areas except under the melinex, leaving distinct white
    stripes, more pronounced on some items than others. We think
    that of those items susceptible,  those that were generally
    yellower to start with are not so obviously altered. Although
    the display was very long-term, general light levels were
    controlled and provided by incandescant bulbs and daylight was
    fairly well excluded, so UV levels were never considered to be a
    problem. Some cases were lit more brightly than others, and
    temperature could be warm. The records show case materials to
    have been tested, although the condition of some objects on
    removal indicates not too well. The worst effected items smell
    of paper acid/lignin, and the discolouration is similar to the
    usual lignin/UV reaction.

    We do not want a repeat of this effect in the new permanent
    displays, and if melinex does provide added protection from
    residual UV we would like to take advantage of this. However we
    are afraid that wrapping a sheet of melinex around the back of
    the mount board could a) create a microenvironment, b) cause
    problems with reflection.

    Has anyone else experienced similar observations?

    Can anyone suggest alternative methods of support?

    Are we correct in our diagnosis of very low UV levels acting on lignin
    over time?

Jane Pudsey
Senior Conservator
Arts and Heritage
Community Services Directorate
The Herbert
Jordan Well
Coventry CV1 5QP
+44 24 7678 5171
Fax: +44 24 7622 0171


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                  Conservation DistList Instance 21:14
                   Distributed: Tuesday, July 3, 2007
                       Message Id: cdl-21-14-015
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