Jackets are required -- to protect important books. Translucent glassine covers can replace missing or torn jackets, or can be layered over jackets you want to preserve. To make one, open a book flat on a sheet of acid-free glassine (available at archival supply houses). Trace around the outside, adding to each side a flap nearly as wide as the cover; add 1 1/2 inches to the top and bottom. Set aside the book. Fold the top and bottom edges over, and crease sharply, then wrap the book snugly.
Glassine sheets available from:
New York Central Art Supply
62 Third Avenue
New York, NY 10003