=Library Binding.=—The average library is spending about six percent of its total income on binding. The newer and smaller libraries spend less because their books have not yet come to need the binder’s attention. The older and larger libraries spend more because of the large number of books needing to be rebound and the numerous periodicals taken. The essentials of good library binding are durability, flexibility, neatness, high grade of materials and suitability of style. Library bookbinding is distinct from the ordinary machine made “case” or publisher’s cloth binding and the decorative binding favored by bibliophiles and amateurs. The weak points in modern book making are poor paper, imperfect sewing, poor attachment of the book to the cover, lack of flexibility in the back and joint, perishable leather and cloth used in the binding. The results are that leaves become loosened, the joints broken and the linings of the hollow backs come off and the boards separate. The present tendency is to strengthen weak joints by using double boards, inserting between them the linings and tapes on which the book is sewn. Much of the durability of a binding depends upon the quality of glue used. The cost of glue used on a book cannot always be determined by the price paid per pound, since the cheaper glue will not cover as much surface as the higher grade glue which absorbs more water. The cheap article is a great detriment to the life of the paper, the free opening of the book and the flexibility of the back. “Flexible glue” as made in this country is a misnomer. To say the least it is not all that the manufacturers claim for it. =Leather.=—The old saying that there is nothing like leather for wear no longer holds true. Modern leather is much less durable than old leather. Modern leather bindings decay mainly because of improper methods of tanning, the use of dried and cured skins of inferior quality; the use of acids and other injurious agents in the bleaching and dyeing processes, the removal of the natural oils and the splitting and artificial graining of the skins. Red and some shades of brown are the colors found to be most durable. Many of the bright colored dyes seem to hasten decay. Leathers that look alike may wear very differently. Names applied to various grades mean less and less. The experience of recent years with the leathers used in book binding has led librarians to a wider use of book cloths of various kinds.