Storing photographic materials

Maria Karen Sigurdardottir <mks [at] rvk__is> writes

>Can somebody give me a information about which material is better
>polyethylene or polypropylene as a storage pages for photographic
>materials?

Both are "safe" if they are uncoated but which is "better" depends
on a number of factors, only some of which I'll address here. First,
these are not the only options in plastics. Polyester (e.g. Mylar
Type D) has greater clarity and a higher melting point in case of a
fire, so it is preferable to either polyethylene or polypropylene.
The stiffness of polyester and polypropylene is an advantage over
polypropylene because enclosures with flaps make insertion and
removal of the item less likely to result in damage than sleeves.
However, from the standpoint of cost, polyethylene is "best" because
it is cheapest.  It also has a very low melting point compared to
the other plastics.  Also, choice depends on the future use of the
photographic material is to be stored.  For materials which will not
be frequently viewed, I prefer paper sleeves or envelopes to any of
the plastics.  Paper is definitely preferable to plastic for nitrate
and acetate negatives to absorb acids emitted as deterioration
byproducts.

Gary D. Saretzky
Archivist, Monmouth County Archives
Coordinator, Public History Internship Program, Rutgers
Chair, New Jersey Caucus,
Mid-Atlantic Regional Archives Conference

                                  ***
                  Conservation DistList Instance 13:29
                 Distributed: Friday, November 12, 1999
                       Message Id: cdl-13-29-005
                                  ***