Dear Colleagues;

We have an exhibit which will be up for another two years.  We are looking
for ways to make cases more resistant to dust infiltration.  The cases are
large, floor-standing style cases with glass fronts.  The opening height is
7' and varies in width.  The principal entrance of dust into the cases is
from the gap between the glass panels.

Any recommendations for ways to seal those gaps with an average width of
1/4"?    Some space must be maintained between the glass in order to remove
the panels for access to the case interiors.

Thanks in advance.

Whitney Watson