Criteria for deacidification

A frequent dilemma in selecting conservation treatments for material
selected for 'conservation' is whether or not, and how, to deacidify.
This is often simply decided at the discretion of the chief conservator,
using an unwritten grid of updated information and accumulated
experience. Given the unchallenged need and value of this discretion,
would it not be useful to begin forming and sharing general
decision-making procedures for this treatment? These larger grids would
be a valuable foundation for discussion and training for collection
conservators. So, here goes. This is an experimental draft which is not,
as yet, a part of our procedures here at Northwestern. I am hopeful of
developing something out of it, and solicit your comments.

                   CRITERIA FOR DEACIDIFICATION

The following categories for deacidification must fulfill the following
conditions before they may be put into affect:

-the material has permanent value to the collection and will not be re-
formatted

-the material will not be altered by the process in a way that will
physically or visually detract  from its original condition

-paper has a pH of 5.5 or below

I. AQUEOUS DEACIDIFICATION
     a. non-circulating material with artifactual value
     b. handmade paper
     c. wet treatment will not harm images
     d. wet treatment will benefit paper

II. NON-AQUEOUS SPRAY DEACIDIFICATION
     a. all material to be encapsulated
     b. material that would be damaged or altered by AQUEOUS
        or mass treatment
     c. material that does not fall under category I. but is
        receiving in-house complex conservation treatment

III. MASS DEACIDIFICATION
     a. material in circulating general collections
     b. material in category I. that would not benefit by wet
        treatment
     c. (other criteria as developed through dialogue with
        the Preservation Office)

IV. MATERIAL DEFERRED TO FUTURE M.D./STRENGTHENING PROCESS (???)

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                  Conservation DistList Instance 4:56
                  Distributed: Sunday, April 28, 1991
                        Message Id: cdl-4-56-004
                                  ***