Under certain conditions, the pasting on of a so called correction may be a very disagreeable task. If errors have been made in composing or printing a page which escaped notice and correction at the proper time, a revised page is printed, and this must be inserted by the binder in the place of the faulty one. This inserting is done after the folding; the faulty leaf is so cut off that a narrow margin is left in the back to which the rectified leaf is pasted.

If maps or plans accompany the work these also must be inserted; thin sheets need simply be pasted on the back edge like other sheets and fixed in their right place; but thick paper is not easily pasted on and, besides, would always pull away the next leaf. It is therefore joined to a narrow strip of paper about 1 cm in width and this is pasted and fixed in the back. If several plates have to be inserted at the same place, or to be fixed at the end of the book, they are joined together in sections of suitable thickness. For this, thin paper is hinged in the back of the book, that is, the two plates are pasted over each other after pasting a narrow margin of about 3 mm. When dry, the double leaf so obtained is folded together in the middle of the pasted little guard. As this process lessens the leaf which has the back fold by as much as is pasted to the other, the latter is cut down by 3 mm. beforehand.

If there are many such plates to be joined together, they are made up in sections of 4 or 6 according to the thickness of the paper, and every 2 or 3 cut down accordiI1g to circumstances, and the same number left the full size. When all have been properly cut, the edges are fanned out and pasted. Then as many as make up a section are taken up and fanned out a little further, the pasted edge of No. 1 is laid on 6, 2 on 5, 3 on 4, and the batch set aside on the left and the same process gone through with the next lot. When dry, the plates thus guarded together are creased together at the back.

Plates on thick paper must likewise be mounted on strips of paper. These are cut from thin, strong note paper and are so arranged that their thickness in the back is the same as the thickness of the plates. It is well to select a paper which when double is as thick as the plates. In case the plates are extra thick, the guard is made four fold. The width of the guard must be measured to correspond. If a guard of double thickness only is required for filling up, it is cut twice the width of the guard and 3 mm. added for pasting on the plate. This gives 2 x 1 cm. + 3 mm. = 23 mm. If a guard of four fold thickness is necessary, the result is 4 x 1 cm. + 3 mm. = 43 mm. The plates are fanned out narrowly with the back edge uppermost, pasted, and each plate affixed to one of the made guards. This work is called "mounting on guards."

When the pasted plates are dry they are folded in the back on the following plan according to whether the guard must be two fold or three fold.

Thus the folded guard completely fills out the space in the back of the book. Besides, two, three, or more plates can easily be made into a section if the little guards are made up within each other.

Forwarding Part 5