Carton and case labels: ITF-14 and GS1-128 on the outer box

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The barcode on a single product is not the barcode on the box it ships in. When you sell wholesale, send cases to a 3PL, or receive cartons from a supplier, the outer box needs its own code - a GTIN-14 printed as an ITF-14 symbol, or a GS1-128 that also carries the batch and quantity inside. This guide covers which carton code to print, how wide it has to be to scan, and how LabelCraft prints it.

The item code and the carton code are different numbers

A retail unit carries a GTIN-13 (an EAN-13) or a GTIN-12 (a UPC-A) - the number a till scans. A case of, say, 12 of that unit gets its OWN number, a GTIN-14, so a warehouse can scan the whole carton in one beep instead of opening it. The GTIN-14 is built from the item's GTIN plus a leading indicator digit (1 to 8) that marks the packaging level, with a fresh check digit recalculated over all 14 digits.

ITF-14: the standard carton code

ITF-14 (Interleaved 2 of 5, 14 digits) is the symbology made for outer cases. It encodes exactly 14 digits - a GTIN-14 - and nothing else, so it is always the same width: LabelCraft's engine counts it as a fixed 126 modules (bars, spaces and quiet zones) no matter the number. Because corrugated cardboard is a rough print surface, the standard frames the code with a thick bearer bar and prints it large, so a forklift or dock scanner reads it cleanly from a distance.

How wide a carton barcode has to be to scan

A barcode scans only when each of its narrowest bars is at least a couple of printer dots wide. Because an ITF-14 is a fixed 126 modules, that sets a hard minimum width for the whole symbol at any print resolution. LabelCraft works it out from the very engine that prints your labels:

At 203 dpi (a typical direct-thermal carton printer): at least 31.5 mm wide to scan at all, and about 47.3 mm for comfortable headroom.
At 300 dpi: at least 21.3 mm wide, about 32.0 mm comfortable.
These are the floor below which the bars fall under one printer dot and the code stops reading - not a target. GS1's own carton artwork is larger again; on a real shipping case, bigger always scans better.

If you place an ITF-14 in a box narrower than its floor, LabelCraft does not silently shrink the bars under the readable limit. It warns you before the roll prints - the same never-silent rule the whole engine follows, so a too-small carton code is caught at design time, not at the receiving dock.

When to use GS1-128 instead

Use GS1-128 when the case label has to carry more than the GTIN alone - a batch or lot number, a best-before date, or the exact quantity inside. GS1-128 packs those into one symbol using Application Identifiers: (01) for the GTIN-14, (37) for the count, (10) for the batch and (17) for the expiry. It is the format most warehouse and 3PL receiving systems expect on a mixed or perishable case. See GS1-128 Application Identifiers for the exact element strings LabelCraft builds.

Printing carton labels in LabelCraft

In the template editor, add a barcode element and set its format to ITF-14 (a plain carton GTIN) or GS1-128 (to add batch, date or quantity).
Size the element box to your carton label stock - the widths above are the floor; on cardboard, larger is safer.
Print at 100% scale (never "fit to page"), so the bars keep the exact width the engine calculated.
Labelling a received transfer? Generate the carton labels straight from Receive and label.

LabelCraft prints the symbol at its exact size to ±0.1 mm and never quietly prints a code too small to scan, so a carton you label reaches the next warehouse readable the first time.

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