Blocking of 20th century coated papers

Amanda Clydesdale <mandyc [at] aocscot__co__uk> writes

>Among the material we are freeze-drying for a client are a number of
>bound volumes of "Country Life", between 1900 and 1930; they are
>printed on semi-gloss glazed paper. Many of them had dried around
>the edges before they could be salvaged: these dried areas remain
>stuck together after freeze-drying, although can be separated with
>care and the application of a small amount of IMS.

If the books have begun to dry and blocked before freezing, I think
it will be an idea to soak them in water again before freezing and
freeze-drying. After freeze-drying and if the papers still are
blocked, the only thing to do will be:  carefully use your
bone folder to separate the leaves.  Probably after this, the paper
will need some dry-mount repairing.

    **** Moderator's comments: Soren wrote back and added:

    By a chance I came over an article in Restaurator 1:4 1970 page
    245-247: Protein "Surgery" by O. Wendelbo & B. Fosse, where they
    separated blocked art paper by use of The enzymatic "scalpel":

       "Trypsin (crystalline) was chosen, as this enzyme hydrolyses
        peptides, amides, esters etc. at bonds involving the
        carboxyl group of argine and lysine.  Glue from collagen
        contains lysine, so does casein.  The preliminary
        experiments gave excellent results: Complete separation
        without harm neither to text nor illustrations."

    Contact me by mail and I will sent you a copy of the article.

Soren Ibsen
Conservator
Norwegian University of Science and Technology
University Library of Trondheim
Gunnerus Library
N-7034  Trondheim
+47 7359 2132
Fax: +47 7359 2100

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                  Conservation DistList Instance 12:42
                 Distributed: Monday, November 9, 1998
                       Message Id: cdl-12-42-002
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