Tight Backs
For tight backs cut a guard of firm, thin cloth, such as cambric or jaconet, about three-fourths of an inch wide and as long as the book. Sew the section to the middle of the guard, and paste the guard to the book, one-half to each of the adjoining leaves. Press this guard well back into the book. This can be done only when the adjoining pages are securely held.
It frequently happens that a book in the original publisher's cover becomes loose at the joint, because the super used as back-lining cannot stand the strain put upon it. Ordinarily, a book defective in this manner should be bound at once; but if it is deemed best to attempt mending it, a strip of jaconet should be cut 1-1/4 inches wide and the length of the book. Paste one-half of this to the cover and the other to the adjoining fly-leaf, thus transferring the strain from the super to the fly-leaf. This method can also be used to mend a break in the middle of a book, but should never be used if the book must eventually be rebound.
Another method of mending a loose joint is to remove the book entirely from the cover, sew on new end papers guarded with muslin, and cover the back of the book with canton flannel which extends three-fourths of an inch on each side. When dry, paste the entire back of book and sides and put the book back into the cover, pasting down the new end paper. This is, in effect, recasing. (See page 184.)
Sometimes books which are loose at the joints and have loose signatures may be mended by applying paste with a long-handled paste brush to the backs of the signatures. This must never be done if it is possible that the book will need to be rebound later.
Fly-Leaves
To add new fly-leaves, cut paper suitable for this purpose the same length as the old fly-leaves and one-half inch wider. Fold over this one-half inch, paste it on the outside and attach it to the old fly-leaf. If necessary, this may be used as a new end paper and pasted to the cover over the old end paper. If used as an end paper, the book should be pressed promptly to prevent it from warping.
Repair of Maps
All old or mutilated maps or charts must be flattened out by placing the maps between large millboards with heavy weights over them, before they can be inserted in books. Repairs may be made with onion skin paper or any other thin, tough paper, the same as is done with torn leaves in books. If the map is very old and valuable, it may be advisable to use paper which resembles in a way the texture and color of the map itself.