Boxes provide books with structural support and protection from dust, dirt, light, and mechanical damage. Books of great importance merit boxes to prevent damage whatever their condition. Artifactually important volumes with damaged bindings that need to be retained should be boxed rather than treated when treatment would alter their value or character. Damaged books that have low value or are rarely used and do not warrant treatment or repair of the binding should also be boxed. Very thin, small, fragile, limp, or oddly shaped books need boxes to hold them in shape, to protect them during handling, and to protect them from adjacent volumes on the shelf.
The two types of boxes appropriate for most books are the drop-spine box (Figure 1), also known as the clamshell or double-tray box, and the phase box (Figure 2). Drop-spine boxes provide better support and protection from dirt and light than do phase boxes. Because they are complex structures, they also provide some protection from changes in relative humidity, which phase boxes do not.
Phase boxes were originally intended as a temporary preservation measure; books were housed in phase boxes while they awaited conservation treatment. Although they are less rigid and impervious to light and dust than drop-spine boxes, phase boxes have nevertheless become an acceptable, cost-effective storage medium. They are now available in various styles with different types of closures.
Many commercial library binderies make button-tie phase boxes. Phase boxes with drop-spine structures or four-flap wrappers that close with Velcro coins are available from several companies. These drop-spine and four-flap phase boxes are generally less expensive but require staff time for assembly. They take up slightly less shelf-space than conventional button-tie boxes. Otherwise, these phase boxes and button-tie phase boxes are more or less equivalent in protection provided and stability of materials. Some companies make all of their phase boxes from lignin-free board. Lignin-free button-tie boxes are available but may need to be requested and cost slightly more than those made from "acid-free" board.
Slip cases (Figure 3) should not be used to hold books because bindings are abraded as books slide in and out of them. In addition, book spines are unprotected from light.
It is important to fit a box accurately to the book. A loose fit does not provide the necessary support and allows the book to shift inside the box, exposing it to the abrasion which the box was constructed to avoid. A tight fit can cause damage to the edges and joints of the cover.
The materials used to construct a box should be permanent, durable, and acid-free. For phase boxes, materials should also be lignin-free and buffered if possible.
Whether you construct your own custom-fitted book boxes or order them from suppliers, you may be faced with measuring the height (H), width (W), and thickness (T) of the books to be boxed (Figure 4). The easiest way to do this is by using a measuring device such as the MEASUREpHASE™, available from many commercial conservation suppliers.
A similar device can be made at home or by a carpenter with plywood, cardboard, and a ruler (Figure 5). If, however, you must measure books by hand, the following tips may be helpful.
You can consult the Members page of the Library Binding Institute, check your regional chapter of the Guild of Book Workers, or check your local telephone directory for individual binders in private practice who make drop-spine boxes. We suggest that you obtain information from a number of vendors so that you can compare costs and assess the full range of available products.
This preservation leaflet is an update of the 1999 leflet written by Richard Horton, Conservator, Bridgeport National Bindery, Inc. NEDCC gratefully acknowledges Margaret R. Brown, upon whose 1999 drawings the current illustrations were based.