d. If books are thin, it is best to put labels on lengthwise. If very thin, put labels on front covers, near the back. If labels project over the back, trim with scissors.
If books have been used or have already had labels, the process is the same, except that no ammonia need be used.
Old labels which have been shellaced are hard to remove. The best way is to apply ammonia and water to the label, allowing it to soak in. When thoroughly moistened, remove with a dull knife. Removing dry labels by scraping with a knife injures the back of the book.
LETTERING
By Hand
It is sometimes feasible to letter with ink on the back of a book instead of putting on a label which holds the lettering. If the surface be glazed, it can be broken down with diluted ammonia, or sometimes merely a damp cloth will be sufficient.
So far as possible, letter with black India ink. Carter's white ink is the best for lettering dark colored cloths. It is sometimes difficult for a novice to use white ink, but it can be handled satisfactorily if one uses a stub pen which is kept perfectly clean and is always wiped before being dipped in the ink. Shake the bottle often and add water if ink is too thick. Gold ink should never be used.
When lettering is dry, apply shellac as described under Labeling.
With Type
Some of the larger libraries have found it economic to have a binder's printing outfit for lettering call numbers on all books, even when the library does not bind books. Such an outfit may be used of course for lettering author and title, but there will be little occasion to do this except in connection with a regular bindery. Call numbers, however, are so much more legible and permanent when put on with type that it should always be done whenever the number of accessions is sufficiently large to warrant the employment of some person to do the work. It does not, however, need experienced finishers and, if time permits, may be done by regular library assistants after some instruction and practice. It will be discovered, however, that lettering in gold on cloth is more difficult than on leather. For the benefit of those who wish to try it the following description is given.