LETTERING BLOCK.—A piece of wood, the upper surface being slightly rounded, upon which side labels are lettered.
LETTERING BOX.—A wooden box in which hand-letters are kept (see HAND-LETTERS).
LINING-PAPERS.—The coloured or marbled paper at each end of the volume. Called also end-papers.
MARBLER.—One who marbles the edges of books and paper.
MARBLING.—The art of floating various colours on a size, from which it is transferred to paper or book edges. To stain or vein leather like marble.
MARKING-UP.—When the back of a book is being marked for flexible sewing.
MILL-BOARD.—The boards that are attached to the book. Various kinds are in use now; the most common is made of straw, the best of old naval cordage.
MITRED.—When the lines in finishing meet each other at right angles without overrunning each other, they are said to be mitred. Joined at an angle of 45°.
MUTTON-THUMPING.—A term used in bygone days, indicating the common binding of school books in sheep-skin.
MUTTON-THUMPER.—An old term indicating a bad workman.