8. Cloth must be used for sides of all books bound in half-leather or half-duck. Never use marbled paper except occasionally on newspapers.
9. Unless otherwise specified, cloth which conforms to the specifications of the Bureau of Standards, or Imperial morocco cloth, must be used for full binding. For sides of leather bound books a somewhat cheaper grade may be used.
10. Duck should have a twisted, double thread in the weft.
11. Moroccos or pigskins must be guaranteed by the manufacturer to be free-from-acid.
12. Glue must be best quality of binders' or flexible glue, and must be used sparingly.
13. Poor materials of any kind must not be used.
14. In taking books apart, all old glue, paste, back-lining, paper, etc., should be carefully removed.
15. The binder should expect to do a certain amount of mending of torn pages and guarding of weak signatures, but should be allowed to charge extra when the amount is excessive.
16. The text of all books must be collated by binder and imperfect books returned to the library. (See under Processes, Collation, [p. 15]).
17. All illustrations of whatever character printed on single leaves must be guarded with thin, tough paper and the guard folded around the adjoining sections.