broken ( broken back )
1. The tendency of a book to open readily at a
place or places where the binding has been forced
or strained, causing the book to lose its shape.
This may be caused by: 1) improper opening of a
new book that is tightly bound; 2) improper
backing, which flattens the spine and affects its
contour; 3) using paper with the grain running at
right angles to the spine, resulting in leverage
and causing THROW
OUT of one or more sections; 4) sections,
either with or without plates, that are too bulky,
and are forced apart during backing, leaving
ridges; and 5) the use of animal glue during the
gluing process before rounding and backing, that
is too cold or is not sufficiently flexible. In a
TIGHT BACK leather
binding, it may result in ridges appearing on the
spine where the leather has been forced away from
the paper. 2. A book broken completely through so
that it is in two or more pieces. This generally
occurs in relatively old books, particularly those
of the 19th century, in which the paper and glue
have become so embrittled and inflexible that when
the book is opened, it breaks apart. (83 , 102 )