Where the checks happen, and what they catch
A defect is cheapest at the stage before it exists. That is why inspection sits at four points in the process rather than at the end — a colour problem caught at the press costs a reprint, the same problem caught after packing costs the shipment.
The four checkpoints
Incoming material
Sheet thickness, film clarity, board weight and colour are checked against what was ordered before the material enters production. A batch of PET that measures 0.4 mm instead of 0.5 mm will fail at the customer, not here — unless it is caught on arrival.
First-off approval
The first units off the line are inspected against the approved sample and the approved print. Nothing continues until this comparison is signed off, because a press that is slightly out of register at unit one will be out of register at unit ten thousand.
In-process inspection
Periodic pulls during the run, checked for print register, colour against the approved standard, dimensions, lid fit and surface defects. The interval is set by the size of the order and the number of processes involved.
Final inspection before packing
Finished units are checked for count, carton marking and packing list against the order. This is the last point where a wrong count is still cheap to fix.
What each checkpoint is actually looking for
| Register between colours, ink coverage, colour measured against the approved proof rather than a screen, and whether small type is still legible at the final size. | |
| Dimensions | External size, wall thickness, cavity depth and lid clearance. Measured with calipers, not by eye — a box that looks right and is 0.3 mm tight will not close in a cold warehouse. |
| Forming | Corners, crease lines, seal strength on blisters, and whether a fold sits square. A crease that is 1 mm off shows up as a lid that never sits flush. |
| Surface | Scratches, scuffing, glue squeeze-out at the seam, fingerprints under a gloss lamination, and window film that has pulled away at a cut corner. |
| Fit | The product is placed into a finished unit at the sample stage. A pack that passes every dimensional check and still does not accept the product is the failure this step exists to prevent. |
What you receive
- A physical pre-production sample to approve, before the run starts.
- Production photographs during the run, on request — useful when the order has to be signed off from another continent.
- A packing list stating units per carton, carton count and gross weight, issued before shipment.
- Cartons marked to an agreed format, so the count can be verified on arrival without opening every box.
The inspection standard itself — sample size, acceptance level, which defects are critical — is agreed in writing per order rather than quoted as a fixed figure. A promotional pack and a medical-device tray do not deserve the same acceptance criteria, and applying one number to both is how either gets over- or under-inspected.
When something does fail
- It is caught before packing where possible. Failed units are pulled and the cause is identified — tooling, material batch or machine setting — before the run continues.
- You are told, not surprised. If a batch will miss the agreed standard, the choice between a delay and a concession is yours, and it is presented with the actual numbers.
- After delivery, transport damage is documented with photographs of the outer carton and the affected units, so the claim sits with the carrier rather than being absorbed silently.
Need your inspection criteria applied?
Send the acceptance criteria your QA team uses. If they can be met on our lines we will say so; if they cannot, better to know before the tooling is cut.