ITF-14 is the GS1 implementation of an Interleaved 2 of 5 (ITF) bar code to encode a Global Trade Item Number. ITF-14 symbols are generally used on packaging levels of a product, such as a case box of 24 cans of soup. The ITF-14 will always encode 14 digits.
The thick black border around the symbol is called the Bearer Bar. The purpose of a Bearer Bar is to equalize the pressure exerted by the printing plate over the entire surface of the symbol, and to enhance reading reliability by helping to reduce the probability of misreads occurring when the bar code is scanned at too large an angle so that the scanning beam crosses the top and/or bottom edge of the bar code rather than scanning across all bars--called a "short scan". However, for ITF-14, the Bearer Bar is not really needed to detect a short scan. Because the length of the data in an ITF-14 bar code is always 14 digits, even when a short scan appears to read valid data, the error can easily be detected by the fact that the read data is shorter than 14 digits; then the bar code can be re-scanned to correct the error. The main value of the Bearer Bar for ITF-14 is to improve the first-scan read success rate by enhancing the uniformity of printing pressure and bar edge definition, especially when ITF-14 bar codes are printed on corrugated cardboard, which is common.