The importance of moderate temperature and thorough ventilation of libraries cannot be too much insisted on. With proper conditions of ventilation, temperature, and dryness, books may be preserved without deterioration, for very long periods, on open shelves.
On the other hand, as a general rule, tightly fitting glass cases conduce to their preservation.
Leather bindings that have been coated with glair or varnish seem to keep better than those without.
The bookbinder shares, in no small measure, with the leather manufacturer and librarian, the blame for the premature decay of leather bindings.
Books are sewn on too few and too thin cords, and are not firmly laced into the boards. This renders the attachment of the boards to the book almost entirely dependent on the strength of the leather.
The use of hollow backs usually throws too much strain on the joints in opening and shutting the book.
If the headbands are not strong the leather of the back is apt to become torn.
The leather is often made very wet and stretched a great deal in covering, with the result that, on drying, it is further strained, almost to breaking point, by contraction, leaving a very small margin of strength to meet the accidents of use.
The use of oxalic acid for washing backs of books, or of leather for bookbinding, is fatal to durability. Vinegar, even in its pure state, is injurious.