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.
_Tools._ The tools necessary are a pallet to hold the type; four fonts of brass type (lead, or type other than brass should never be used); long-bladed knife with straight edge for cutting gold leaf; cutting pad; gas burner similar to the burners on cook stoves; and a frame with wooden screws in which to hold the book while it is being stamped.
_Materials._ The materials needed are the best American gold leaf, cotton batting, sweet oil, some specially prepared rubber for removing the excess gold leaf, and glaire.
The tools or materials which are used exclusively by binders can be obtained from any binders' supply house. Glaire is easily made as follows:
Take whites of three eggs; add three teaspoonfuls of vinegar and beat until it is a light froth. Let stand a few hours and strain through a piece of muslin into a bottle. If kept corked glaire will keep for some time.
_Process._ 1. Place on finishing bench, backs up, books on which call numbers are to be gilded.
2. With a small sponge, apply the glaire to the part of the back which is to receive the call number, taking care to draw the sponge evenly across the back, leaving a straight line. If the application of glaire makes that part of the book appear radically different from the rest of the back, the glaire may be applied to the entire back. It should not be allowed to run over on the sides. Allow the glaire to dry thoroughly.