Scientific Foundation for the Conservation of Documents, by S.A.Dobrusina and E.S. Chernina. Edited by E.G. Vershinina. Russian National Library, St. Petersburg, 1993. 126 pp., soft cover.Reviewed by Margarita Blank
This book is addressed to paper conservators and students in conservation. It describes the chemical processes taking place in paper, ink and colors during their manufacture, use, damage, aging and conservation. Also included is a survey of the major research projects conducted mostly in the Conservation Department of the Russian National Library (RNL).
According to the National Standard of Russia, developed with participation of the Conservation Department of RNL, the term "conservation of a document" refers to preservation of documents by means of indoor environmental control, restoration and stabilization.
Indoor environmental control includes light control, temperature and humidity control and protection of documents from mold, insects and dust.
Restoration of documents consists of mechanical, chemical and enzyme cleaning, repairs, fills by leafcasting or by hand, reinforcement, resizing, lamination and encapsulation.
Stabilization is treatment of a document to slow down its aging and to prevent damage.
The book describes various types of damage caused by fungus in paper, and the symptoms of the infection.
Information is provided on pigments and natural colors obtained from plants or organisms as well as on other materials used in early manuscripts. The problem of verdigris pigment in Dutch maps of the 16th and 17th centuries is described, along with ways to treat it.
After careful research, formaldehyde* is recommended to kill mold, as a less toxic contemporary remedy. The products of decomposition of formaldehyde (CO and H2) do not affect the paper, and the excess of formaldehyde can be treated with ammonia, producing harmless urotropine (methenamine). According to research, formaldehyde provides a high level of disinfection.
Also described are the various methods of paper cleaning. The most problematic vegetable oil stains yield to common solvents like toluene after treatment by deep freezing. The precise temperature should be maintained for every type of paper fibers. A list of solvents and their combination is suggested for oil stain removal. Various methods of stain removal by enzymes and bleaching are also discussed. An effective yet delicate bleaching is achieved by using chloramine-B.*
To prevent spreading of very unstable aniline ink on paper in the process of conservation and water treatment, the use of either phosphore-tungstic acid or chitosan is suggested, depending on the chemical nature of the ink. Solutions of ethyl cellulose, Ftorlon (a fluorine-based polymer) and Regnal (a mixture of polyvinyl acetates) are recommended for fixing water colors and writing inks before water treatment and bleaching.
A wide variety of documents, from prints and printed books of the 15th to 20th centuries to manuscripts with insoluble inks and leaflets, undergo restoration by leafcasting. Credit for inventing and developing the leafcasting method belongs to the Conservation Department of RNL. Now the fourth model of the machine is in use. It makes possible a very high level of productivity and quality.
Another mechanical method of paper conservation, lamination, is widely used for protection of contemporary newspapers, maps, pamphlets and catalog cards.
A method of paper stabilization by sequestering ions of heavy metals such as iron and copper by chelating agents has been developed and is now recommended for use along with traditional methods.
The last chapter of the book is devoted to methods for evaluating the durability and permanence of paper. It discusses various tests and approaches to the prognosis of paper longevity, including the calculation of activation energy for the process of paper degradation and the correlation between the results of destructive and nondestructive methods.
Also presented is a graphic approach to the problem of color matching of paper used in conservation.
The book is supplied with a large body of references and ends with a list of the major publications on conservation of paper in Russia and abroad.
* These methods (fumigation with formaldehyde and bleaching with chloramine-B) are not in use in the United States.