About ITF (Interleaved 2 of 5) Barcodes
Interleaved 2 of 5 (ITF) is a high-density, numeric-only 1D barcode symbology. It is called "Interleaved" because it encodes digits in pairs: the first digit of a pair is represented by the width of five bars, and the second digit is encoded in the width of the five spaces that lie between those bars. This interleaving technique allows ITF to pack numbers tightly, making it one of the most space-efficient linear barcodes for numeric data, particularly on corrugated cardboard shipping boxes.
How ITF (Interleaved 2 of 5) Encoding Works
ITF encodes numbers in pairs, which means the input data must always have an even number of digits (if an odd number of digits is entered, a leading zero is typically added). For each pair of digits, two of the five bars are wide (hence "2 of 5"), and two of the five spaces are wide. The barcode starts with a specific start pattern and ends with a stop pattern. While ITF is self-checking, a modulo-10 check digit is often appended to avoid partial scans (where a scanner only reads a portion of the barcode).
Common Applications and Industries
ITF is the standard barcode for packaging shipping containers, outer cartons, and logistics labels. Because of its large, bold bars, it can be printed easily on coarse surfaces like corrugated cardboard. It is also used in manufacturing and warehouse distribution. The most common packaging variant of ITF is the ITF-14 barcode, which is used to encode GS1 Global Trade Item Numbers (GTINs) for shipping cases.
Advantages & Limitations
ITF offers very high data density for numeric strings and scans reliably even when printed on low-quality, rough materials like cardboard. The main disadvantage is that ITF is vulnerable to "short reads" or partial scans if the scanner does not read the entire barcode width. This risk is minimized by using solid black border boxes (bearer bars) around the barcode and adding a check digit.