Quick answer: enter a number with an even number of digits – if it is odd, a leading zero is added for you (or the check digit makes it even). Turn on the check digit and bearer bars if your scanners expect them, then download the barcode.
How “interleaved” works
The bars encode the first digit of each pair and the spaces between them encode the second. Every digit uses five elements, two of them wide – hence “2 of 5”. Because bars and spaces both carry data, ITF is one of the most compact linear codes for long numbers, which is why the carton barcode ITF-14 is built on it.
The one weakness: short reads
ITF has no fixed length and its start and stop patterns are simple. If a scanner beam crosses only part of a barcode at an angle, it can occasionally decode a shorter, valid-looking number. Three things prevent this:
- set your scanners to accept only the length you use (for example exactly 10 digits),
- add a check digit, and
- print bearer bars above and below the code.
How to create an Interleaved 2 of 5 barcode
- Type the number. Digits only. ITF encodes them in pairs, so the total (including any check digit) must be even.
- Check digit and bearer bars. Add the mod-10 check digit if your system uses one. Bearer bars stop scanners from reading half a barcode as a shorter number.
- Test. The scan test confirms that the bars decode to your number.
- Download. PNG for labels, SVG or PDF for print artwork.
Typical uses
Warehouse bin labels, cartons in distribution (as ITF-14), photo-lab film envelopes, airline baggage systems in the past, and many industrial applications where only numbers are needed. For anything with letters, use Code 128.
ITF and other 2 of 5 codes
Several older codes share the “2 of 5” idea. Industrial 2 of 5 and Matrix 2 of 5 encode data only in the bars, which makes them much wider. IATA 2 of 5 was used on airline baggage tags, and COOP and Datalogic 2 of 5 appeared in European retail systems. All of them can be created in the main barcode generator, but Interleaved 2 of 5 is the only one still in wide use.
Choosing the bar width
ITF uses a wide-to-narrow ratio of between 2:1 and 3:1. With a bar width of 0.33 mm, an 8-digit ITF is about 34 mm wide including quiet zones. For labels printed on corrugated board or with thermal printers at 203 dpi, use 0.375 mm or wider.
Frequently asked questions
Why was a 0 added to my number?
ITF encodes digits in pairs, so it needs an even number of digits. A leading zero does not change the value of the number.
Is Interleaved 2 of 5 the same as ITF-14?
ITF-14 is a specific use of Interleaved 2 of 5: exactly 14 digits (a GTIN-14) with bearer bars and GS1 sizes.
Is the check digit printed?
Yes, when you switch it on it is added to the bars and to the text line.
Can I use ITF for letters?
No. Interleaved 2 of 5 can only encode digits 0–9.