What grain is
Board is made from fibres that mostly lie in one direction. It folds cleanly along that direction and cracks across it, and the difference is visible on the first fold rather than after a hundred.
On a rigid box the grain is chosen at layout, before the die is made. Changing it afterwards means a new die.
Why a fold cracks
A crease across the grain breaks the surface fibres. On a plain board that shows as a white line; on a printed board it shows as a broken line through the print, which is what customers notice.
Scoring depth helps and does not fix it. The fix is laying the part out the right way round on the sheet.
What the cutting die does
A steel rule die cuts the outline and creases the folds in one pass. Everything on the box that is a straight edge, a tab or a fold is decided by that die, and it is made from your drawing rather than from a sample.
An error in the drawing becomes an error in every box, which is why the pre-production sample is approved before the run and not after.
What a die cannot do
A steel rule die cuts through; it does not carve, bevel or make a partial-depth cut reliably across a run. Where a design needs a recess or a chamfer, that is a different process and it is worth knowing at drawing stage rather than at sampling.
Very small internal cut-outs and very tight internal corners are also limits — the rule has to be bent to the shape, and there is a minimum radius it will take.
Reusing the die
The die belongs to your job and is held for it. A reorder of the same box uses the same die, and only a change to the shape needs a new one — a change to the colour or the logo does not.
At a glance
| Decision | Where it is made |
|---|---|
| Grain direction | At layout, before the die |
| Fold and tab positions | In the cutting die, from your drawing |
| Recesses and chamfers | A separate process — flag at drawing stage |
| Reorders | Same die, no new tooling |
Frequently asked questions
Why did my boxes crack along a fold?
Almost always the fold running across the board grain. Scoring helps but the real fix is the layout on the sheet.
Can you change the shape after the die is made?
Not without a new die. Colour and logo changes do not need one; shape changes do.
Is there a minimum size for a cut-out?
Yes — the steel rule has to be bent to the shape and there is a minimum radius. We will tell you at drawing stage if a detail is below it.
Do I pay for the die again on a reorder?
No, if the shape is unchanged. The die is held for your job.
Tell us what you need
Tell us the piece, your brand and the quantity you have in mind. We’ll send photos of our work and one clear, all-in quote.