"D" rings are very popular and it's part for the clean (rivetless) spine of the binder. Most importantly, page contents don't turn when the book cover is opened, so holes won't wear as much — binders are easier to close — and indexes and pages are neatly in line to give the catalogue an orderly well organized appearance.
Round Ring Binder
Round rings are still North America's most popular design because of their durability and ease of leafing through papers. Rings are usually spine mounted — but could be mounted on back covers as well, for more aesthetic appeal.
Actual size Layout Templates are available to you, in a PDF Format, for easy artwork set up. Position of rivets change according to binder size.
