thumb index ( thumb cuts )
A type of INDEX
which utilizes a series of rounded notches cut
into the fore edge of the book. Each generally has
a label bearing a letter or letters indicating the
arrangement. The index proceeds from head to tail
and front to back of the volume. The maximum
number of thumb cuts, and therefore the number of
letters represented by each, depends on the height
and thickness of the book. The thumb index is used
principally for Bibles and dictionaries. The cuts
are usually made by a machine designed for the
purpose. Also called "cut-in index." (264 )