The old “joints” must be knocked out of the sections of books that have been previously backed. To do this, one or two sections at a time are held firmly in the left hand, and well hammered on the knocking-down iron fixed into the lying press. It is important that the hammer face should fall exactly squarely upon the paper, or it may cut pieces out. The knocking-down iron should be covered with a piece of paper, and the hammer face must be perfectly clean, or the sheets may be soiled.
CHAPTER III
Guarding—Throwing Out—Paring Paper—Soaking off India Proofs—Mounting very Thin Paper—Splitting Paper—Inlaying—Flattening Vellum
GUARDING
Guards are slips of thin paper or linen used for strengthening the fold of leaves that are damaged, or for attaching plates or single leaves.
Fig. 8.
Guards should be of good thin paper. That known as Whatman’s Banknote paper answers very well. An easy way to cut guards is shown in [fig. 8]. Two or three pieces of paper of the height of the required guards are folded and pinned to the board by the right-hand corners. A series of points are marked at the head and tail with dividers set to the width desired for the guards, and with a knife guided by a straight-edge, cuts joining the points are made right through the paper, but not extending quite to either end. On a transverse cut being made near the bottom, the guards are left attached by one end only (see [fig. 9]), and can be torn off as wanted. This method prevents the paper from slipping while it is being cut.