Liner.
1. A sheet of paper of an appropriate thickness
attached to the inner surface of the board of a
book, usually one that is to be fully covered in
leather. The liner causes the board to curve
convexly to the text block. This curvature will be
straightened by the shrinkage of the leather which
covers the outside of the board. In order to
prevent warping of the cover at a later time, the
grain direction of the lining paper should be
parallel to the spine of the book. 2. The outer
layers of any kind of paperboard which varies in
color or quality from the middle or other parts of
the board. (139 ,
335 )