Bound book with detachable pages

摘要

The book has a number of pages printed on one or both sides, joined to each other in the region of the spine of the book. There are lines of perforations (4) in at least some of the pages in the region near the spine, to enable these pages to be detached and stored separately. The perforation lines are roughly parallel to the spine. Each perforation line may consist of partial cuts instead of numerous perforations, or the weakening of the line may be carried out in some other form. The detachable pages may have apertures for a ring binder, near the perforation line. Some of these may be elongated. They are symmetrical to an axis of symmetry running at a right angle to the spine.