Bookbinding and the Conservation of Books
A Dictionary of Descriptive Terminology

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break

1. The parting of adjacent sections of a book due to failure of the sewing. See also: START . 2. A crack in the gold or foil BLOCKING or tooling of a book. 3. In papermaking, a complete separation of the web of paper, either on or off the machine. 4. In leather manufacture, the minute wrinkles formed when the grain surface of leather is bent so that its grain side is sharply concave. If the wrinkles formed are very fine. and there are many of them to the linear inch, the leather is said to have a fine break, whereas if they are large and there are relatively few to the linear inch, the leather is said to have a coarse break. A very important aspect of the "break" in leather is that when the leather is flexed to cause the break to appear, it should disappear once the leather is again flattened. Since a fine break is considered to be one of the more important characteristics of leather, tanners attempt to obtain as fine a break as possible. In order to achieve this, it is necessary to prevent excessive cohesion of the fibers in the grain surface of the leather, which is one of the major purposes of FATLIQUORING leather. Break is influenced to a great extent by the amount of oil in the grain layer and increases in fineness with an increase of oil.

The butt area of a skin usually has a finer break than the belly; tighter skins have finer breaks than looser ones, and a leather like calfskin will have a much finer break than cowhide.

Improper methods of finishing may cause an otherwise fine break to become coarse, but the kind of tannage has little effect on break. (102 , 248 , 363 )




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