The edges of leaves on very soiled books may be sandpapered. In this case the book should be held very firm, if possible in a vise.
To Prevent Mildew or Mold
Occasionally books are accidentally soaked with water. In many a fire more damage is done by water than by fire. In such cases it may be a waste of time and money to reclaim ordinary books which can easily be replaced. It is a different matter when it comes to rare books and especially to manuscripts which cannot be replaced. Mr. J. I. Wyer, Jr., director of the New York State Library, in his annual report for 1911 describes as follows the method used in that library after the disastrous fire of that year.
The first step was to remove all covers. Each volume was then taken apart leaf by leaf, and each sheet was laid between print paper for drying. After twenty-four hours every leaf was again handled and placed between heavy blotting paper; after twenty-four hours here, each leaf was again removed to a second blotting paper. At all of these stages pressure was applied to facilitate the drying and keep the documents from wrinkling.... When each leaf had thus passed through these three drying processes, those belonging to the same volume were collected and carefully tied up in boxes or separate packages to wait until all the manuscripts were thus treated.... When all were dried, the manuscripts were arranged in volumes.... The rarest pieces will in time be mended, nearly all will be covered with crepeline, all will be mounted on fresh paper and carefully bound into new volumes.
Covers
Covers may be cleaned by the same materials as those used on pages, but the best method is to wash them with soap and water. For this reason the use of a washable cloth for covers, such as keratol, durabline, or fabrikoid, is an advantage. Miss Margaret Brown, in her pamphlet on mending, Library handbook No. 6, advises the use of a wash as follows: "Two parts good vinegar and one part water. Apply with a clean cloth and rub hard until dirt is removed, then place upright to dry. This should not be used on leather."
Grease spots may be removed from both leather and cloth by covering with a blotter and ironing with a hot iron. The same method will partially remove paint or varnish.
For a great variety of cleansing receipts see Coutts and Stephen's "Manual of library bookbinding," Chapter X.
Covers that have warped must be dampened and put under pressure.
Shellacking of covers has been advocated by some librarians, but it is doubtful if it pays. It may be used in the interests of cleanliness on books bound in light colored cloth and on books in towns where the atmosphere is very smoky. It is a process which takes some time since two coats of shellac must be applied, and it does not increase the wear of the cloth to any great extent. As a regular part of preparing the book for use it takes more time and material than it is worth.