Maps are best mounted on the finest linen (which takes up the least room in thickness), cut a little larger than the map, with an additional piece left, on which to mount the extra paper, which throws the map out. The latter is trimmed at its back first, then brushed with rather thin paste; the pasting-board being removed, the linen is laid on, gently rubbed down, and turned over, so that the map comes to the top; the white paper is then placed a little away from the map, and the whole is well rubbed down, and finally laid out flat to dry. The paste must be clean, free from lumps, and used very evenly and moderately. The map, when dry, is trimmed all round, and folded to its proper size - a little smaller than the book will be when cut.
With all folded maps or plates, a corresponding thickness must be placed in the backs where the maps go, or the foredge will be thicker than the back. Pieces of paper called guards, folded 1/4-l in. in width, according to the size of the book, and placed in the back, are sewn through as a section; but care must be taken that the guards are not folded so large as to overlap the folds of the map, or the object of their being placed there will be defeated. It is easy to ensure the pasting being straight along the edge of a paper plate by placing a strip of waste paper to mark the limit and receive the spreading of the brush.
Having placed the plates, go through them again when dry, see that they adhere properly, and break or fold them over up to the (lasting, with a folding-stick, so that they will lie flat when the book is open. Coloured plates should be looked after during the whole of binding, especially after pressing. The gum on their surfaces may cause them to stick to the letter-press; in this case do not try to tear them apart, but warm a polishing iron, and pass it over the plate and letter-press, laying a piece of paper between the iron and the book to avoid dirt. The heat and moisture will soften the gum, and the surfaces can then be very easily separated. Rubbing a little powdered French chalk over the coloured plates before sticking them in, acts as a preventive.
If a book is entirely composed of single leaves, it should be collated properly and the plates placed in their places, squared and broken over, by laying a straight-edge about 1/2 in. from the back edge, and running a folder under each plate, thus lifting it to the edge of the runner. The whole book is then pressed for a few hours and taken out; the back, previously roughed with the side edge of a saw, is glued up, thus. The book is put into the laying press between boards, with the back projecting about 1/8 in.; the side edge of the saw is then drawn over it, so that the paper is rasped; the back is then sawn in properly, as explained in the next section, and the whole back is glued. After drying, the book is separated into "sections" of 4, 6, or 8 leaves, according to the thickness of the paper, and each section is then "overcast" or "over sewn" along its whole length. The thread being fastened at the head and tail (top and bottom), each section is made independent of the others. The sections are then (2 or 3 at a time) gently struck along the back edge with a hammer against a knocking-down iron, to imbed the thread in the paper, or the back would be too thick.
Having placed the plates, the book is put into the press for a few hours, when it will be ready for "marking up" if for flexible sewing, or for " sawing in," if for ordinary work. The presses used by bookbinders are called "stauding" and "laying," the latter name being obviously a corruption of " lying."
For interleaving writing paper between the leaves of letter-press, the book must be properly beaten or rolled, and each leaf cut up with a hand-knife, both at the head and foredge; the writing paper is then folded to the size of the book and pressed. A single leaf of writing paper is fastened in the centre of each section, and a folded leaf is placed to every folded letter-press leaf, by inserting the one within the other, leaving to every other section a folded writing paper outside, putting them all level with the head; the whole book is finally well pressed.
Fig. 181 illustrates methods of inserting guards: in A, a is the guard, 6 the linen hinge, and c the plate; in B, a are the guards, covered on each side with linen, and b are the plates, the dot between the guards indicating where the sewing through takes place; in C, which is B closed, are the linen-covered guards, and 4 the plates.
After having been Tor a night in the press, the book is again collated, knocked straight at both head and back, and put into the laying press between boards, projecting beyond them about i in. The boards are held between the fingers of each hand, and the back and head are knocked alternately on the cheek of the press; the boards being then withdrawn the required distance from the back of the book, the book and boards are held tightly with the left hand, and the whole carefully lowered into the press, the right hand being employed to screw up tightly, holding the book quite straight, and firmly.
If the book is to have "flexible" binding, it is not sawn in, but marked, the difference being that the cord is out-aide the sheets, instead of being imbedded in the back in a groove made by the saw.
For the flexible binding of an ordinary 8vo volume, to be cut all round, the back is divided into 6 equal portions, leaving the bottom or "tail" 1/2 in. longer than the rest, to accommodate an optical illusion, by which, if the spaces were all equal, the bottom one would appear to be the smallest. The marks on the back are exactly squared, and marked pretty black with a lead pencil. The head and tail are next sawn in to imbed the chain of the kettle-stitch, at a sufficient distance to prevent the thread being accidentally divided in cutting. Great accuracy is absolutely necessary in flexible work, especially in the marking up, as the bands on which the book is sewn remain visible after coveriing. a very small book, such as a prayer-book, is marked up fur 5 bands, hut only sewed on 3, the other 2 being fastened on as false bauds when the book is ready for covering.