Export carton marking: three layers, shipping marks, and where corrugated printing fails

1. The short answer: carton copy talks to three different readers

A shipping carton is read by the warehouse (what is it, how many, which batch), by customs and the importer (who is responsible, where was it made, which language version), and by the handler (can it be stacked, which side up, where to sling it). Mix those three into one block of artwork and the barcode gets squeezed, the handling symbols get pushed aside by the logo, and the carton is opened for inspection at the destination.

This page covers three things: what has to be on the carton, what makes a carton barcode scan (the ITF-14 and SSCC numbers are not negotiable), and why printing straight onto corrugated fails — and when a label is the cheaper answer.

2. Three layers of information

3. Laying out shipping marks

• Main mark: consignee code or abbreviation, destination port, carton number (C/NO. 1-20). This is how the terminal and forwarder find the cargo — biggest type on the carton.
• Side mark: product, SKU, quantity, gross/net weight, dimensions, origin. This is the face customs opens and the warehouse counts.
• Additional marks: licence number, language version, order number, warnings — added per market, not on every shipment.

Four layout rules: carton numbers must be consecutive and match the packing list; marks go on at least two faces, because one face disappears as soon as the pallet is built; the real test is legibility at 1.5 m (a working rule is ≥20mm for the main mark and ≥8mm for body text); and never place marks where the sealing tape will cover them.

4. ISO 780 symbols: fewer is better

ISO 780:2015 is the current edition (it replaced the 1997 edition and was confirmed again in 2026). It defines graphical symbols only, and the standard itself says they should be used only when necessary — a carton covered in fourteen pictograms communicates nothing. The commonly used set, with ISO 7000 registration numbers so you can source the correct artwork:

Two recurring mistakes: printing a stacking symbol without the number (three units, 800 kg — otherwise the symbol carries no information), and printing a symbol mirrored or upside down, which at a loading dock reads as a printing defect. Keep symbols at 25mm or more, or they cannot be seen from three metres.

5. ITF-14: the specifications are fixed

Carton codes are almost always ITF-14 encoding a 14-digit GTIN; a pallet or logistic unit uses SSCC (18 digits, carried in GS1-128). Designers shrink or squash the symbol to fit the layout, which is the single most common cause of a carton that will not scan:

SSCC identifies a logistic unit — a pallet, a mixed case, a parcel — with 18 digits (extension digit, GS1 company prefix, serial reference, check digit), usually as a GS1-128 label applied to two adjacent faces of the pallet. The division of labour: the ITF-14 says what the product is; the SSCC says which shipment this pallet belongs to. You need both; neither replaces the other.

6. Why printing directly on corrugated fails

Corrugated is printed flexo, a different precision class from offset or digital label printing. Failures cluster in six places:

1. Absorption and dot gain: the liner drinks ink, so fine dots fill in. Reverse type and hairlines below about 4 pt are unreliable.
2. Flute show-through: pressure differs over flute tips and valleys, so a single line of type prints unevenly.
3. Registration drift: 1–2mm of movement across colours is normal; avoid designs that must align perfectly, such as a thin frame around the whole panel.
4. The barcode gets squeezed: when the panel is tight, the symbol is the first thing reduced — and then it will not scan (section 5).
5. Varnish and film change contrast: a gloss finish reflects and defeats infrared scanning. Never varnish the barcode area.
6. Finishing collides with print: slotting, die-cutting and gluing tolerances eat the quiet zone or clip a symbol.

7. Stacking and transport testing

Before printing "MAX 5 HIGH", ask who calculated it. Compression strength depends on board grade, box style, humidity and time in storage, and a laboratory figure at 23°C needs a discount in a South China rainy season or inside a container. The industry route is ISTA: series 1 is non-simulation integrity testing (vibration and drop, the lowest bar), series 2 is partial simulation, series 3 is general simulation (3A for parcel delivery up to 70kg, 3E for e-commerce unit packaging).

What a printer can realistically do: recommend the board grade from the actual packed weight and stack height rather than defaulting to five-ply; run a compression and drop test on the sample carton and put the result on the carton; and warn that a stacking limit is a short-term figure at ambient conditions — heat and humidity in an ocean container reduce it. Certification reports come from a third-party laboratory; we supply the samples and the board recommendation.

8. Six checks before the cartons ship

1. Carton numbers consecutive and matching the packing list; main and side marks on at least two faces.
2. Origin, importer address and licence/notification number checked word for word against this shipment's customs documents (numbers supplied by the customer).
3. Language version marked, and a mixed-pallet manifest on the outside of any mixed pallet.
4. ITF-14 bar height ≥32mm, magnification ≥62.5% (100% on corrugated), bearer bars present, quiet zones clear, symbol off the score lines.
5. No more than six handling symbols, each with its number or an unambiguous meaning, all the right way up.
6. Stacking limit backed by a test; weights and dimensions measured, not estimated.

9. Three questions buyers ask us

Can we just enlarge our EAN-13 and print it on the carton?

No. EAN-13 is a retail point-of-sale symbol; a carton needs ITF-14 carrying a 14-digit GTIN. An enlarged 13-digit symbol will not read on warehouse scanners, or will resolve to the wrong packaging level. Add the indicator digit (usually 1–8, depending on level) in front of the GTIN-13 to build the 14 digits.

We only have a logo — can you fill in the rest?

The identification layer (product, quantity, weight, dimensions) we can complete from your packing list. The compliance layer we will not invent: importer name and address, licence or notification numbers and the origin statement must come from you or your local importer, in writing. We will lay out the panel and list exactly which fields are missing.

One carton, three markets — what is the cheapest way?

Two options. A shared carton plus market labels: print only the invariant information and put everything market-specific on a label. Or separate print runs per market: higher cost, best appearance. With either, a mixed pallet needs a manifest on the outside, or the destination warehouse will break the pallet and re-inspect.

10. Five things to send with an order

1. Carton dimensions (state internal or external) and what goes inside, with packed weight per carton;
2. Shipping mode: parcel, FCL, LCL or air — it sets the stacking and test level;
3. Destination market, importer name and address, and the local licence/notification number (write "to be supplied" if not yet issued);
4. Whether ITF-14 or SSCC is required, with the GTIN and GS1 company prefix from your side;
5. Quantity and delivery date, and whether you want a sample carton to verify scanning first.

Related reading: Specifying a roll label, When a barcode prints but will not scan, Box styles and board grades, Cosmetic labels for Southeast Asia, Labels for chilled and frozen food, Shipping labels from China to Hong Kong and Southeast Asia, Barcode print quality and scan failures, GS1 logistics labels and SSCC-18.