spine lining paper
A relatively heavy paper, usually kraft, sometimes
coated, and with either a creped or flat finish.
The paper, which is applied with the machine
direction running from head to tail of the text
block, should be of a thickness appropriate to the
size and weight of the book. It is generally
applied over the initial cloth lining of large
and/or heavy hand- and library-bound books. Spine
lining paper is seldom used in edition binding.