What is a packaging mock-up?

A dieline on screen tells you the geometry is arithmetically correct. It does not tell you that the box is a millimetre too tight once the board thickness is taken up at every corner, or that the lid is stiff enough to be irritating, or that the pack does not stand up reliably. Those are physical questions and they need a physical answer.

A structural mock-up is usually unprinted or lightly printed — the point is the structure, not the graphics. Put the product in it. Close it and open it several times. Carry it. Stack two. Almost every packaging problem worth catching is found in the first two minutes of handling one.

In regulated packaging the mock-up has a second role. DRAP’s labelling guideline expects labelling and pack design to be considered at the review of mock-ups, which means the same physical artefact serves both the regulatory file and the print approval. That is a genuine efficiency rather than a marketing point.

The distinction from a proof is worth holding: a proof answers "is the artwork right?", a mock-up answers "is the box right?". Colour-critical jobs need both.

Ask for more than one where the decision is genuinely open. Two mock-ups in different board weights, or two constructions side by side, settle in ten seconds an argument that can otherwise run for a week over email — and at this stage changing your mind costs nothing at all.