Fig. 6.—Dividers
When the sheets of books that have to be rebound have been carelessly folded, a certain amount of readjustment is often advisable, especially in cases where the book has not been previously cut. The title-page and the half-title, when found to be out of square, should nearly always be put straight. The folding of the whole book may be corrected by taking each pair of leaves and holding them up to the light and adjusting the fold so that the print on one leaf comes exactly over the print on the other, and creasing the fold to make them stay in that position. With a pair of dividers ([fig. 6]) set to the height of the shortest top margin, points the same distance above the headline of the other leaves can be made. Then against a carpenter’s square, adjusted to the back of the fold, the head of one pair of leaves at a time can be cut square (see [fig. 7]). If the book has been previously cut this process is apt to throw the leaves so far out of their original position as to make them unduly uneven.
Accurate folding is impossible if the “register” of the printing is bad, that is to say, if the print on the back of a leaf does not lie exactly over that on the front.
Crooked plates should usually be made straight by judicious trimming of the margins. It is better to leave a plate short at tail or fore-edge than to leave it out of square.
Fig. 7.