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Subject: Deterioration of glass negatives

Deterioration of glass negatives

From: Susan Knoer <susan.marie>
Date: Saturday, November 11, 2000
Eli Echols <eaechols [at] newchurch__edu> writes

>At the Raymond and Mildred Pitcairn Archives in Bryn Athyn,
>Pennsylvania, we have a collection of about 4000 Glass Negatives. We
>are only just beginning to address their preservation appropriately,
>and in doing so I have noticed that many of them smell pretty
>strongly of vinegar.

You may be interested in :

    Horvath, David G. 1987. The Acetate Negative Survey Final
    Report: A Project Funded by the University of Illinois and the
    National Museum Act. Louisville, Kentucky:  University of

Describes major study of existing photographic negative collections
from 1925 - 1955 from approximately 30 U. S. collections. Includes
storage recommendations. It's still available from us for $15.00 US
postpaid from

      Photographic Archives
      Ekstrom Library
      University of Louisville
      Louisville KY 40292

The pertinent question is, since the decay product is the acetic
acid which gives rise to the common name of "vinegar syndrome",  do
you want to add acid to your storage area?  I can tell if there are
deteriorating acetates in a box the minute I open it, and sometimes
just in passing.  The archival sleeves are saturated with the smell,
as well as those of poly negs in the same box, so it does migrate to
items not in direct contact.

When we find deteriorating acetates, we make an archival print and
move the negative to a specially built vault in the basement along
with the nitrate negs.  The separate air handling system protects
the poly negs in regular storage area, as well as the thousands of
prints.  If you are storing only negatives in an area with separate
air handling, then the question of whether the poly would be harmed
is outside my small expertise--I'm not a conservator, but work with
photographic archivists.

An excellent bibliography on film storage is at


        **** Moderator's comments: The above URL has been wrapped
        for email. There should be no newline

The Image Permanence Institute is the source of many studies and
probably can point you to more specific studies.

Susan Knoer
Reference Assistant
Special Collections
University of Louisville
Louisville, KY 40292
Fax: 502-852-8734

                  Conservation DistList Instance 14:28
                 Distributed: Monday, November 13, 2000
                       Message Id: cdl-14-28-005
Received on Saturday, 11 November, 2000

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