Storing panoramic photos

Our library was given two panoramic photographs (each is 6 1/2" x 70
5/16") which had been framed at some point.  Each of them is stuck
to the glass that was in the frames.  Our photographer was able to
copy them and he and the photograph curator want to box up the
originals for storage and have patrons use the copies for reference.
They think it would be too difficult to try to remove the photos
from the glass.  Since storage space as at a premium, they have
decided that they want to stand the box with the photos vertically,
on one of it's 6 1/2" ends, between the uprights of adjacent
shelving units.  I was going to make the box by gluing layers and
layers of photographic and binders board together, but because the
photos are so long and skinny, I'm afraid that this won't be strong
enough to keep from bowing.  Would it be possible (safe) to
reinforce the sides with something stronger than board (metal, wood,
sealed with something like polyurethane) sandwiched between layers
of board?  Should we encourage them to find someplace where they can
be stored flat?  We're curious about what others have done in this
situation.

Nancy Edstrom
Conservation Lab
Illinois State Historical Library

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                  Conservation DistList Instance 9:39
                 Distributed: Sunday, November 5, 1995
                        Message Id: cdl-9-39-008
                                  ***