Fig. 49.
The height of the boards for a book that has been trimmed, or is to remain uncut, will be the height of the page with a small allowance at each end for the squares. When a pair of boards has been cut all round, it can be tested for squareness by reversing one board, when any inequality that there may be will appear doubled. If the boards are out of truth they should generally be put on one side, to be used for a smaller book, and new boards got out. To correct a badly cut pair of boards, it is necessary to reduce them in size, and the book consequently suffers in proportion. If the boards have been found to be truly cut, they are laid on the book, and the position of the slips marked on them by lines at right angles to the back. A line is then made parallel to the back, about half an inch in (see [fig. 49]). At the points where the lines cross, a series of holes is punched from the front with a binder’s bodkin on a lead plate, then the board is turned over, and a second series is punched from the back about half an inch from the first. If the groove of the back is shallower than the thickness of the board, the top back edge of the board should be bevelled off with a file. This will not be necessary if the groove is the exact depth. When the holes have been punched, it is well to cut a series of V-shaped depressions from the first series of holes to the back to receive the slips, or they may be too prominent when the book is bound. It will now be necessary to considerably reduce the slips that were frayed out after sewing, and to remove all glue or any other matter attached to them. The extent to which they may be reduced is a matter of nice judgment. In the desire to ensure absolute neatness in the covering, modern binders often reduce the slips to almost nothing. On the other hand, some go to the other extreme, and leave the cord entire, making great ridges on the sides of the book where it is laced in. It should be possible with the aid of the depressions, cut as described, to use slips with sufficient margin of strength, and yet to have no undue projection on the cover. A slight projection is not unsightly, as it gives an assurance of sound construction and strength, and, moreover, makes an excellent starting-point for any pattern that may be used. When the slips have been scraped and reduced, the portion left should consist of long straight silky fibres. These must be well pasted, and the ends very slightly twisted. The pointed ends are then threaded through the first series of holes in the front of the board, and back again through the second ([fig. 50]). In lacing-in the slips must not be pulled so tight as to prevent the board from shutting freely, nor left so loose as to make a perceptible interval in the joint of the book. The pasted slips having been laced in, their ends are cut off with a sharp knife, flush with the surface of the board. The laced-in slips are then well hammered on a knocking-down iron (see [fig. 51]), first from the front and then from the back, care being taken that the hammer face should fall squarely, or the slips may be cut. This should rivet them into the board, leaving little or no projection. If in lacing in the fibres should get twisted, no amount of hammering will make them flat, so that it is important in pointing the ends for lacing in, that only the points are twisted just sufficiently to facilitate the threading through the holes, and not enough to twist the whole slip.
Fig. 50.
Fig. 51.
To lace slips into wooden boards, holes are made with a brace and fine twist bit, and the ends of the frayed out slips may be secured with a wooden plug (see [fig. 52]).