What is a steel-rule die?

Building one starts with the dieline. The plywood base is laser-cut with a slot for every line in the drawing, then rules are bent to shape and hammered into the slots. Cutting rules stand proud and are sharpened; creasing rules are shorter and rounded, so they compress the board instead of cutting it. Rubber ejection strips are glued alongside the cutting rules to push the sheet off the blades after each impression.

That construction has two consequences worth understanding as a buyer. The first is that the die is a real manufactured object with a real cost and a real lead time, quoted separately from printing. The second is that it is specific to one design at one size: change the dimensions by five millimetres and it is a new die, not an adjustment.

It follows that repeat orders in an existing size are meaningfully cheaper, because the tooling already exists and only the print has to be paid for. It also follows that the moment to question a size is at the dieline stage, before the tool is cut — which is exactly why we ask for sign-off there rather than treating it as a formality.

Dies are stored and reused across orders. Ask who owns the die and where it is kept; it matters if you ever move supplier.