Light exposure limits for art on paper and photographs

I was recently appointed paper conservator at the Bergen Art Museum
in Bergen, Norway. The Museum would like to establish an exhibition
policy for art on paper and photographs. Important parts of the
paper collection have been exhibited for too long, under
inappropriate conditions, and are severely damaged. We would
therefore like to have a differentiated policy for light exposure,
which allows us to exhibit the parts of the collection which are in
good condition, while protecting more sensitive objects.

We are inclined to establish a policy built on number of
lux-hours/year, but the difficult part is to choose the upper
limits, especially since the policies used by other institutions
vary widely. To estimate the number of lux-hours that will cause
visible change seems hardly possible for most objects (at this point
we do not have any colour or density measuring equipment).

I would be interested to know how these problems have been solved
(or not solved) at other institutions, and I would also be grateful
for any references concerning this subject.

Jonna Larsen
Conservator of Art on Paper
Bergen Kunstmuseum
Rasmus Meyers Alle 3
N-5016 Bergen
Norway

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                  Conservation DistList Instance 12:26
                Distributed: Tuesday, September 15, 1998
                       Message Id: cdl-12-26-021
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