backing boards
The boards used in hand binding to assist inBACKING a book.
Backing boards are generally made of a very hard
wood and are frequently faced with strips of
metal. The upper edge of the board is beveled at
an angle of approximately 80°, over which
the outer sections or leaves on both sides of the
text block are bent. The board is also thicker at
this edge than at the lower, so that when it is
placed on the side of the text block near the
spine and secured in theLYING PRESS , the
force of the press is concentrated nearest the
spine. (92 , 183 , 335 )