The real protection against outward injury to the book lies in the cover, the inside of which consists of boards more or less strong. Of the kinds on the market the bookbinder uses grey board, which is made from waste paper and rags. It is grey, very tough, and flexible, but dearer than other raw materials.

Straw boards made from straw and waste paper are cheaper, but less flexible, and are easily broken. They take a very high polish under the calendaring machine and become very hard, and are therefore very suitable for some work if flexibility is not essential. They are generally used in all cloth binding.

So called leather boards are unsuitable, for, in spite of great toughness and pliancy, they are certain to cockle and always remain spongy. Wooden boards are unsuitable for bookbinding on account of their small resistance, but are indispensable for fancy goods and portfolios, as they can be so nicely cut and are less liable to subsequent cockling than any other kind.

Besides these, yellow and blue boards are made. These are colored to suit and serve quite special purposes, mostly fancy goods; but they also are not used in bookbinding, on account of their high price.

The thinnest boards are known as middles. This is a strong whitish material made entirely from waste paper. It is used for lining backs, limp bindings, and in all cases where flexibility, together with durability, is required.

In finished work books, fancy goods, maps the boards are never left exposed to view, but are covered with paper, cloth, or leather. For the inner side of the cover of the book white or colored paper is frequently used, note paper of the smallest size being more rarely used.
All marbled or pressed papers are made in one standard size. Besides the end papers for inside of books, a figured paper has of late been made known as "litho printed" for fancy goods. This has been put on the market in the most varied kinds, and also with cloth-like impressions, under the names damask, brocade, and Leipzig end papers. The use of this paper has of late been almost discontinued. The dearest are those printed with designs in gold.

Cloth is more durable than paper, calico being mostly used. This is made in all colors and designs, and was formerly imported from England; but today German manufacturers produce a really good article. Plain linen cloth, black, green, or grey, sail cloth, buckram, moleskin, and beaver are used in the making of account books.

Silk is used in the bookbindery as end papers in extra work, and also for fancy goods and for lining boxes. The lower grades are seldom used, the better qualities being mostly taken.

Today velvet is still used in the bindery, chiefly as a covering for portfolios, albums, and addresses, and except for metal clasps remains without ornamentation.
The bookbinder's best material, to which is given the choicest, most expensive, and most painstaking decoration, is leather in its various kinds. Sheep skin, undyed or split and dyed, serves for school books and other cheap work. Goat skin and morocco are better kinds, the latter being preferable both as regards price and quality.

Morocco is made from the skin of the goat. Morocco, Levant morocco, and maroquin all denote the same kind. It is strong, coarse grained leather imported from the Levant, very tough and durable.

Cape morocco, also called maroquin ecrase, is similar to this. This has a very large, artificially smooth pressed grain, and hitherto has been higher in price than all other leathers.

Calf (matt or polished) is quite smooth and is only used for fine work. Cowhide is this to this, but of coarser texture, and is only used for leather goods, portfolios, and albums; for other work in the bindery it is not easily enough worked.

Celluloid is one of the latest materials used for covers. There is evidently a good opening for this in the wholesale manufactures, stamped goods, and small fancy goods; whilst on the other hand it is of little value to the smaller shops, as it requires machinery for gilding.

Sewing and Pasting