Print QA for branded charcoal packaging: the checklist
By Mohamad Sinno, Charcoal Expert ·
Ask AI for an importer brief:
The checklist
Print quality is verified at two gates that fail in different ways. The artwork proof catches a wrong design. The physical check catches a right design printed badly — and it is the one buyers skip, because the design has already been approved and approval feels final. It is not: what you approved was a file, and what ships is board, ink and glue.
| Group | What is checked | The convention behind it |
|---|---|---|
| Colour | Printed box compared against the approved proof, not against a memory of it | Colorimeters and spectrophotometers verify print colour against the approved artwork — QC Advisor, QC service, modified 23 March 2026 |
| Colour | A tolerance agreed in advance for the colours that carry the brand | Delta E ≤ 2–3 for critical SKUs — ePackFactory, supplier guide, 11 March 2026 |
| Colour | Colour proofs drawn from the actual production run, not from a pre-run sample | Request proofing from the exact production run, with L*a*b* values — Passenpack, supplier guide, 20 May 2026 |
| Register | Multi-colour register checked on the panel with the smallest type — usually the warning | Registration targets of ±0.5 mm or tighter — ePackFactory, 11 March 2026 |
| Structure | External dimensions measured at the centre and at the edges, not once in the middle | ±1 mm, measured at multiple points — Passenpack, 20 May 2026 |
| Structure | Board specification confirmed as the one ordered | Material substitution without approval is a non-conformance — QC Advisor, modified 23 March 2026 |
| Structure | Actual board strength measured on the finished carton rather than taken from the order | “A 32 ECT box isn’t always a 32 ECT box” — flute compresses in manufacturing; caliper measured post-production — Passenpack, 20 May 2026 |
| Finish | Lamination, varnish and any spot finish inspected for lift, haze and misregistration | Proof logs kept and spot audits allowed — ePackFactory, 11 March 2026 |
| Assembly | Glue seams and fold lines checked on assembled boxes, not on flats | Drop, burst, edge-crush and compression testing — ePackFactory, 11 March 2026 |
| Sampling | A sampling plan agreed before the run, so “we checked some” has a defined meaning | AQL plans agreed before full runs — ePackFactory, 11 March 2026 |
| Legibility | Barcode scanned from a finished box, and the warning panel measured against its minimum letter height | Our own gate — the panel is the one element with a size set by an instrument |
| Retention | Printed samples retained against the approved proof for the life of the design | Retained print samples — ePackFactory, 11 March 2026 |
Every tolerance in that right-hand column is somebody else's, and it is named and dated for exactly that reason. We do not publish a Delta E target, a register tolerance or an edge-crush value of our own, because we have not measured and published one — and a borrowed number with our name on it would be worth less to you than a borrowed number with its owner's name on it. Use them as the industry's working thresholds and agree yours with us in writing before the run.
Approval gates and who signs
The first gate is yours alone. Nothing goes to the printing house until you have signed off the proof against the dieline — not our reading of your design, your signature on it. The second gate is ours to run and yours to specify: we check the printed boxes against that approved proof, and what "against" means is whatever tolerance the two of us agreed before the press started.
That ordering matters more than it sounds. A tolerance agreed after a disagreement is a negotiation; the same tolerance agreed before the run is a specification. The industry convention is to settle the sampling plan in advance for the same reason — otherwise "we inspected the run" and "we looked at a few" are the same sentence.
Two structural notes about our boxes specifically, because they change what is worth measuring. The inner is 1 kg inner duplex 250 gsm e-flute, varnished, cmyk — duplex laminated over corrugated board, so the flute can read through the printed face and a heavy solid shows it most. The master is 10 kg master kraft k150/m125k150 b-flute, up to 3 colours, which is a stacking component before it is a printed one; how much load it has to take is a function of how the container is stuffed, and that is a question for the loading plan rather than a number we print here.
Handling a print defect finding
If the defect is found at our end before loading, it is our problem and the boxes are reprinted or the run is rejected. If it is found after the container reaches you, it enters the ordinary claims route: raise it within seven days of receipt, through the export desk or WhatsApp, with photographs and the approved proof to compare against. After that window the goods are deemed accepted. The remedy is replacement or credit on the next order.
The retained printed sample is what makes that conversation short. Without one, a colour dispute becomes two people describing a box over a video call; with one, there is an agreed physical reference on both sides of the ocean. It costs nothing and it is the single most useful thing on this page.
One route avoids the whole cycle. Our house retail designs are always in stock — no print lead time — already printed, already proofed, already inspected — and the only variable left on them is the side-panel sticker. Whether that fits you or not is the first decision, and this checklist is for everyone on the other side of it.
One thing this page deliberately does not cover: the marking a master carton needs because the contents are dangerous goods. That is a shipping requirement rather than a print-quality one, it is set by the dangerous-goods rules rather than by your artwork, and it has its own home — the shipping documents and marking pages. Get the artwork right here and the DG marking right there; conflating them is how a beautiful box gets refused at a booking desk.
Agree the tolerances before the run
Send us the colours that actually carry your brand and the tolerance you want held on them, and we will confirm what the board and the process can do before you commit to a press date. If you would rather judge our print by looking at it, ask for a house box.