Book jackets and wrappers protect books and pamphlets from dust and consequences of physical handling. They should be made from Mylar, which is a type of inert polyester. Plastics vary greatly in chemical stability and should be used with caution. Some plastics are unstable chemically and produce by-products as they deteriorate that can accelerate the breakdown of paper. Others contain plasticizers that can cause items in contact with them to stick to their surface and media to bleed11. Three types of plastic meet conservation standards: polypropylene, polyester, and polyethylene. Some plastic covers can break down and eventually contribute to acid migration12.
If you intend to display your valuable materials, it is wise to take the following measures. First of all, if you are using a display case, make sure that it has minimal subjectivity to direct sources of light. Optimally, light levels should be no more than 50 lux. Cover fluorescent bulbs with ultraviolet filters. If you choose to have the book open when it is on display, make sure it is open less than 180 degrees, as that places the least strain on the spine and joints. A book cradle will effectively support the spine of the book. Also, make sure to turn the pages on a continual basis, so that no single page is receiving total exposure to light. If you wish to display a book as it sits on a shelf, you should utilize a book shoe. A book shoe is similar to slipcase, but has no top. It will hold the book closed, and the support will remove much of the strain on the text-block of a vertically standing book. It essentially allows the book to be partially displayed while on a shelf, yet be supported on all three sides.
As a general rule, the less a book is handled, the better. Environmental factors not withstanding, improper or continual handling of reading material will cause inevitable wear and tear. If you must handle a book or form of printed material, take some simple precautions:
1. Wear gloves. Your hands contain natural oils and other possible contaminants, such as food, dirt and chemicals which, when transferred to a book, will cause damage. Simple cotton gloves can be purchased from any library or archival supplier (See Resources for specific vendors). If you are unable to use gloves, wash your hands prior to handling the book.
2. Do not lay the book flat; rather, support the covers with a cradle or rolled fabric. This will protect the spine and joints from strain from usage.
11 Choosing Archival-Quality Storage Enclosures for Books and Paper,” in Preservation of Library and Archival Materials, A Manual, 2nd ed. Sherelyn Ogden, ed. (Washington, DC: American Association of Museums; 1994), 136.
12 American Institute for Conservation of Historic and Artistic Works. Caring for Your Books. Washington, DC: American Institute for Conservation of Historic and Artistic Works 1997, 2.
