This information is also available in Analysis of Paper , Second Edition, Revised and Expanded, by B. L. Browning, Marcel Delcher Inc., New York and Basel, 1977. As added protection from the formation of acid, paper-based storage materials may have a buffer, such as calcium carbonate, added during manufacture. The purpose of the buffer is to neutralize acids as they form in the storage materials. Suppliers of storage materials should be able to provide information regarding the type and amount of alkaline buffer used. Many papers and conservation mounting boards contain three per cent calcium carbonate.
Buffered materials are appropriate for the storage of most books and artifacts on paper.
Common exceptions include works of art that contain dyes or pigments sensitive to high alkalinity, collages with wool or silk components, cyanotypes, diazo reproductions, and some types of photographs. 4 Molecular Traps A recently developed type of storage material, based on the combination of one or more alkaline buffers with a molecular trap, either activated carbon or zeolites, is intended to protect items better than storage materials that contain only an alkaline buffer. These new storage materials provide protection against environmental pollutants and by-products of deterioration that do not react with the alkaline buffer in the storage material. Research indicates that acidic pollutant gases in the environment are not neutralized by an alkaline buffer in storage materials, and that these gases pass through the storage materials unaltered. It is assumed that other pollutant gases also pass through buffered storage materials unchanged.