Books that have torn leaves mended may be put into the press, but it is not strictly necessary. When very much of this mending is done pressing is impossible unless a standing press is at hand.
A few books such as Granger's Index and some of the Poole's Index volumes should have the first few pages entirely reinforced with cloth. The best cloth for this purpose is crepeline, through which the text can be easily read. When applying it put a thin layer of paste on the leaf and then put on the cloth. The book should then be pressed, first protecting adjoining pages with paper.
Loose Leaves
Loose leaves may be inserted in several ways:
1. Lay a piece of white paper over the leaf, allowing one-eighth of an inch of back margin of the leaf to project. Paste this exposed surface and attach it to the adjoining leaf in the book, pressing down firmly. This can be done only when adjoining leaves are firm.
2. Sometimes the leaf when inserted will extend beyond the fore edge of the book. Trimming of either back margin or fore edge is inadvisable. It is possible to turn over about one-eighth of an inch of back margin, using some kind of straight edge for this purpose. Apply paste to turned over part and press the fold well down into the book. This will give more freedom to the leaf than if one-eighth of an inch has been cut off and another eighth of an inch pasted.
3. Fold strips of thin bond paper cut with the grain, three-fourths of an inch in width, through the center. Paste the outside. Attach the loose leaf to one side and attach the other side to the adjoining leaf in the book. It will be necessary to work quickly because the paper strips when wet will cause a wrinkling of the leaf. This method can be used only if adjoining leaf is firm, but can never be employed with overcasting.
4. If necessary to use as little paste as possible, apply paste to a piece of common soft string by drawing it over a board covered with paste. Then draw the string through the book at the back. The leaf may then be inserted.
Loose Signatures
Ordinarily when one signature becomes loose others speedily follow, and the book must be sent to the bindery unless it is withdrawn absolutely. Sometimes, however, one section will become loose when the rest of the book is firm and solid, sometimes also the use a book will receive does not warrant binding. In such cases, if the book has a loose back, open the section in the middle and place it in its proper place in the book. Thread a darning-needle with Hayes' No. 25 thread (or Barbour No. 40), pass the needle through the hole at top of the section (the kettlestitch hole) in such a way as to bring it out at the top of the book between the book and the loose back. Draw thread through, allowing a few inches to remain inside the section. Drop needle through the loose back, insert it from the back through the kettlestitch hole at tail of the book. The thread can then be tied to the thread projecting at the upper kettlestitch hole. This is a makeshift, but may answer if the book is not to receive hard usage. If the back of the signature is badly worn, mend it by guarding with jaconet on the outside, or by pasting a strip of bond paper down through the center of the fold.