Bearer Bars on ITF14 Symbols – Why Should You Always Use Them?
You learn something new every day.
For years I’ve thought that the only reason to use bearer bars around an ITF-14 barcode is to improve the image quality in the flexographic printing process. As their name implies, the bearer bars “bear” the impression force and protect the narrow bars from spreading and distortion from the flexible plate.
Bearer Bars are not only for bearing the impression force
While that it true, it is not the only reason to use bearer bars with an ITF-14 symbol. In fact GS1 recommends the use of bearer bars with all ITF-14 symbols, including those printed with on-demand technology such as thermal transfer. Why?
It has to do with the nature of the ITF-14 which is the only barcode with the possibility of a partial read. Partial reads can occur when the symbol is skewed in relationship to the scanner, such that only a portion of the barcode is decoded. This is possible because of the way the ITF-14 symbology is engineered. Without going into the details, suffice to say it is a known fact in the barcode technical community.
Use bearer bars with all ITF14 symbols no matter how they are being printed
When thermal transfer printing the ITF-14, putting a bearer bar above and below the bars in the symbol prevents a partial read by disrupting the total bar-space pattern count detected by the scanner, and signaling a misread, which is much better than a successful partial read.
Since the bearer bar used in thermal transfer printing does not actually “bear” any impression force, it can be narrower than the bearer used in flexo printing. The GS1 specification calls for it to be 2X or twice the width of the narrow element, and it need not extend into the area over and atop and beneath the quiet zones.
The nominal width of the bearer bars used in flexo printing should be 0.19 inches and must surround the symbol.
An important word of caution: make sure the surrounding bearer bar does not encroach into the quiet zones. This is a consideration not only at the design stage, but also at the printing stage. Leave enough space so that the quiet zones will be intact even if the bearer bars spread excessively in printing.
Don’t violate quiet zones with surrounding bearer bars
The rule of thumb with quiet zones is that too much is always fine; too little is always a problem.
Let me know what you have experienced with bearer bars and printing barcodes on corrugated. And let me know of other topics you would like to hear about.