Linear symbology
ITF-14
ITF-14 encodes a 14-digit GTIN on shipping cartons and cases, and is built for printing directly onto corrugated board where finer symbologies break down. Its bars are wide and forgiving, and it is normally surrounded by a bearer bar that stops a partial scan being read as a complete one.
Specification
These are the values the editor enforces while you design, not figures collected from elsewhere — the same numbers its quiet-zone and resolution checks run on.
| Property | Value | In context |
|---|---|---|
| Minimum X-dimension | 0.495 mm | 0.0195 in · 19 thou |
| Quiet zone | 10 modules | 4.95 mm at the minimum X-dimension |
| Dimensionality | Linear (1D) | Read by laser or imager |
ITF-14 at 203, 300 and 600 dpi
A printer can only place whole dots, and 0.495 mm is not a whole number of them at any of these resolutions. What changes is how much a single dot of rounding costs you as a share of the narrow bar.
| Resolution | Narrow bar in dots | Printed as | Rounding error |
|---|---|---|---|
| 203 dpi | 3.96 | 4 dots | 1% |
| 300 dpi | 5.85 | 6 dots | 3% |
| 600 dpi | 11.69 | 12 dots | 3% |
What ITF-14 encodes
Exactly 14 digits — a GTIN-14, which is the case-level identifier for a trade unit. Digits only, fixed length, no letters or punctuation.
Where it is used
- Outer cases and cartons of retail goods
- Trade units moving through distribution rather than across a checkout
- Direct print onto corrugated board, where ink spread rules out a fine symbology
Check digit
Starting from the rightmost data digit and working left, multiply the digits alternately by 3 and 1, add the results, then subtract the total from the next multiple of ten. The remainder is the check digit. The editor computes it for you, and accepts the value either with or without it.
How ITF-14 fails in practice
- Omitting the bearer bar. It is not decoration: it prevents a scan that clipped the edge of the symbol from decoding as a shorter, valid, wrong number.
- Printing it too small. ITF-14 has the widest minimum bar of any symbology here precisely because it is designed for a surface that spreads ink, and shrinking it removes the tolerance it was given.
- Encoding a GTIN-13 with a leading zero as though it were a GTIN-14 without confirming that is what the trading partner expects.
When to use something else
Questions about ITF-14
- What is the bearer bar for?
- It frames the symbol so that a scan which only caught part of the barcode fails rather than decoding a shorter valid number. Interleaved 2 of 5 is vulnerable to that particular misread, which is why the bearer bar is standard practice on ITF-14.
- Why does ITF-14 need such wide bars?
- It is designed to be printed directly onto corrugated board, where ink spreads into the surface and fine bars close up. The wider minimum bar is the tolerance that makes printing on that surface reliable.