This is a book review.
To cite this article: (1965) BOOK REVIEWS,
Studies in Conservation, 10:2, 72-81,
To link to this article: https://doi.org/10.1179/sic.1965.012
W. H. LANGWELL,The Postlip Duplex Lamination Processes. Journal of the Society of Archivists.Vol.2, no. 10, pp. 471-6 (1964).
This is a description of a process in which the document to be strengthened is laid between two sheets of thin paper which have been impregnated with poly-vinyl acetate resin mixed with various other materials. The sandwich is pressed and heated to fuse the layers together. Alternatively the resin may be softened with a solvent and pressed cold on to the document. An important feature of the method is the presence of a deacidifying salt in the tissue. This, it is claimed, makes unnecessary a separate deacidification of the document.
The process is presumably intended not only for documents that are much used but also for those which are thought worth preserving for a long time. I do not think that it should be used for the second purpose.
The method is presented without experimental evidence of its merit and without proof of its permanence. The reader should compare this article with two accounts of the work done in testing the effect on paper of plastic and other impregnants: W. K. Wilson and B. W. Forshee, US National Bureau of Standards Monograph, NO.5 (1959), and W. J. Barrow, Permanence/ Durability of the Book, W.J. Barrow Research Laboratory, Richmond, Virginia, U.S.A. 1963-. (A review of Barrow precedes this review).
The nature of the components of the tissue is not clear and changes have been made in its composition since the article was written. It is now not easy to get good adhesion by the hot process. If the document is damped before treatment the adhesion is good, but there is a tendency for the colouring matter in the release paper to stain the document.
Obviously the method is still in an experimental stage, but there is no hint of this in the article.
Some other passages deserve comment. The recipe for an indicator ink ends: (add) 'soda solution to mid green colour.' This is ambiguous, only sodium hydroxide will do.
The suggestion that formaldehyde can be used to make parchment amenable to the process should be backed by a reference to some experimental work on the long-term safety of such chemical alteration of the parchment. There are other assertions which are not so easily accepted that a reference to original work is unnecessary, notably the claim that deacidification occurs throughout the thickness of the paper.
This method may be sound, but the article leaves an impression that the author is tinkering with materials whose chemistry is obscure but whose survival is important.
Victoria and Albert Museum, London
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