Light exposure limits

In planning a long term exhibition (five to seven years) that  could
possibly include works on various papers (fine art and non) as well
as paintings and 3D objects.  What suggestions might some of you
have as to increasing the ability of these prints to stay up for
longer periods of time without receiving serious light damage,
specifically, for a period of more than a year?  What we currently
do is enclose them in museum frames with protection behind UF3 plexi
and closely monitor the light levels in the gallery.  Are there any
contemporary methods used to increase the time a print can stay on a
wall?

Joseph Delci
Chicago

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                  Conservation DistList Instance 13:31
                Distributed: Tuesday, November 23, 1999
                       Message Id: cdl-13-31-020
                                  ***