Fig. 14.
Maps or diagrams that are frequently referred to in the text of a book, should be “thrown out” on a guard as wide as the sheet of the book. Such maps, &c., should be placed at the end, so that they may lie open for reference while the book is being read (see [fig. 14]). Large folded maps or diagrams should be mounted on linen. To do this take a piece of jaconet and pin it out flat on the board, then evenly paste the back of the map with thin paste in which there are no lumps, and lay it on the linen, rub down through blotting-paper, and leave to dry. Unless the pasting is done evenly the marks of the paste-brush will show through the linen. If a folded map is printed on very thick paper each fold must be cut up, and the separate pieces mounted on the linen, with a slight space between them to form a flexible joint.
Fig. 15.
A folded map must have in the back of the book sufficient guards to equal it in thickness at its thickest part when folded, or the book will not shut properly (see [fig. 15]).
PARING PAPER
For paring the edge of paper for mending or guarding, take a very sharp knife, and holding the blade at right angles to the covering-board, draw the edge once or twice along it from left to right. This should turn up enough of the edge to form a “burr,” which causes the knife to cut while being held almost flat on the paper. The plate or paper should be laid face downwards on the glass with the edge to be pared away from the workman, the knife held in the right hand, with the burr downwards. The angle at which to hold the knife will depend on its shape and on the thickness and character of the paper to be pared, and can only be learned by practice. If the knife is in order, and is held at the proper angle, the shaving removed from a straight edge of paper should come off in a long spiral. If the knife is not in proper order, the paper may be badly jagged or creased.