Hammermill Computer Papers Guide to Computer Printers

octavo : A book whose page size is approximately 12 inches by 9 inches. The size is based on a sheet of paper 25 inches by 38 inches, the size of paper traditionally used by book printers, which has been cut into eight pages.

bumped : Indicates that the affected part of the book has been impacted in such a way so as to cause a flattening, indention, or light bending.