5. Attached back.
6. Commercial silk headband.
7. First and last leaves used as pastedowns.
8. Edges uncut.
II.
CASE BINDING.
Case Bindings or casings (for the craft binder refuses to call them bindings) are those covers which are made separately from the books and laid on. These covers have the characteristics enumerated in the specifications and are the unsubstantial covers usually found on modern cheap, temporary books.
If the book is to be bound from original sheets, each sheet is folded into a section. Such a section is called a signature. The number of leaves in a folded sheet or section gives the name to the book. A sheet folded once, making two leaves, is a folio; twice, making four leaves, a quarto or 4to; three times, making eight leaves, an octavo or 8vo; four times, making sixteen leaves, a 16mo; etc. It is seen by this that owing to the varying sizes of paper, any form of book may vary greatly in size. However, the following may be taken as a general standard of sizes:—
16mo 5×7 inches.
Octavo (8vo) 6×9 inches.
Quarto (4to) 10×12½ inches.