The book size resulting from folding a sheet of
paper with three right angle folds, thus producing
a leaf one-eighth the size of the sheet and
forming a 16-page section. To define fully, the
paper size must also be stated. The typical book
paper, for example, which is 25 by 38 inches, will
give an untrimmed book size of 12 1/2 by 9 1/2
inches. Also called 8vo or 8°.