Standard ring configuration:
At Binders By The Box, we install both round rings and "D" type ring mechanisms into our binders. Both styles are backmounted with exposed black rivets on back cover. Both of these styles fit in the same sized binder case.

Capacity Measurement:
To determine the capacity of round rings, measure the inside diameter of the ring. For "D" or "angled D" ring, measure the straightest part of the ring mechanism. Please do not refer to the spine size to determine the capacity.

Hole punching:
The industry standard center-to-center measurement for punching to fit on a letter size 3 ring mechanism is 4 ¼" center to center. The industry standard center-to-center measurement for the punching to fit on a legal size 4 ring mechanism is 3 ½" center-to-center.

Sheet Size:
Our industry standard states the binding edge measurement first to ensure correct paper orientation (portrait vs. landscape) and therefore the sheet size mentioned on this website are 14" x 8  ½" (14" x 9" max) and 11 ½" x 8  ½" (11 ½" x 9" max).

Index divider allowance:
To meet general industry guidelines a tab allowance is built into our binders allowing up to an industry standard  ½" tab extension. This means a 9" wide sheet (max) will fit into our binders.