Mull. See Super.
Octavo. Book printed on paper folded into eight leaves. Usually written 8vo. Loosely used to indicate that the size of a book is between eight and ten inches in height.
Off and on. Term used in machine sewing, meaning that certain stitches in each signature are skipped.
Off-set. Marks made on opposite page because the printer's ink had not become thoroughly dry. In case of illustrations tissue paper is frequently inserted to prevent this. Also called set-off.
Opened edges. See Edges opened.
Out of boards. A book trimmed before the boards have been fastened to it.
Out of print. Not obtainable from the publishers.
Overcasting. Process of sewing single leaves over and over. Also called whipstitching. See page 23.
Pallet. A tool used in lettering having an adjustable box for holding type securely, with a handle attached.
Panel. 1. Space between raised bands, or between stamped lines on the back. 2. A square or rectangular space on the side of a book, whether sunken or enclosed by beveled edges or gilded lines.