Polyethelene plastic is the most desirable for use in storing objects. The
polyurethane and other polymers used in plastic bags off-gas and can damage
dyes and other aspects in artifacts. You can buy rolls of polyethelene by
the pound for about $150 - $175. Using a heat sealer which costs around $35
you can them cut and seal your artifacts for about $0.02 a bag. When you
open the bag you can reseal it, leave ventilation holes if you do not have
temperature and humidity controls in your collections storage. The
polyethelene is porous as are all plastics. The superstition that
non-animate, non-lung-possessing objects need to "breathe" or the fear of
condensation should not worry if the orginal environment in which the
objects were bagged is adequate. The mini-atmosphere held within the bag
will not leach through the plastic for about 8 hours. If the environmental
controls failed on your collections storage area you would have a window of
time to get the machinery back online. If the time extends past that, cut
open the bags. We have economically and safely used polyethelene bags in
the above described manner for about four years with not one bad incident
involving, fine art, natural history, and ethnographic objects of all
classes. There have been some who have advised against using plastic with
metal but these warnings have not proven to be caused by any measurable
evidence. It took me a while to convince others about this system but time
has continued to show nothing but good results. The Smithsonian has used
this type of bagging for many years. Though there continue to be fears and
worries from those who haven't used this storage, I haven't found any real
evidence against the preferrability of the polyethelene over other
plastics.
 
Paul Apodaca
Curator of Native American Art
Bowers Museum
Santa Ana, CA
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Paul Apodaca
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