Sizing Cardboard Inserts for Any Shelf Depth

The half-inch rule

Order each cardboard insert ½″ shorter than your shelf depth. The bracket sits on the front rail, the panel slides into its slot, and the back of the panel needs to clear the rear rail by about ¼″ on each side.

Example: a 24″ deep shelf takes a 23.5″ insert. A 18″ shelf takes a 17.5″ insert.

Common depths

12″ shelf → 11.5″ insert. 18″ shelf → 17.5″. 24″ shelf → 23.5″. 30″ shelf → 29.5″. 36″ shelf → 35.5″.

Heights are flexible — order whatever vertical separation you need, typically 8″–14″.

Why we cut the cardboard for you

Our brackets accept any 4mm-thick sheet, so you can absolutely cut your own. The reason most customers order ours: a clean utility-knife cut on 200+ panels takes 4–6 hours and the edges still come out fuzzy.

We cut on a laser-guided rotary die at $0.75/insert. Edges are dead-flat and the geometry matches the bracket slot to 0.1mm.

Mixing sizes in one order

The configurator lets you add multiple insert sizes in the same order — useful when your warehouse has mixed shelf depths. Each row gets cut, banded, and labeled by dimension.