I want to print bar codes in a document to be printed on an ordinary printer…

With the increase in office automation and the growing use of applications such as document tracking and workflow monitoring, there has been a steady growth in users wishing to incorporate bar codes into documents they are printing. Sometimes the easiest solution is to stick a previously printed label onto the document, but this is not always possible or desirable.

Using Windows bar code fonts

The widespread use of Microsoft Windows has led to bar code TrueType fonts for Windows becoming available, either separately or as part of labelling packages.

Using these fonts can be an apparently easy way to incorporate bar codes in documents that are being produced in Windows applications. However, it is not always that simple and some care needs to be taken.

Firstly, not all bar code symbologies lend themselves to being adequately or correctly represented as individual characters in a font. The Interleaved 2 of 5 (ITF - see page 8) symbology for example encodes two digits in each of its elements, so it is, strictly speaking, impossible to represent a single digit character in an ITF font. Windows-based bar code labelling packages know this and handle the ITF font accordingly, but your word processor and spreadsheet packages will not!

Similarly, fonts that use special start and stop codes, and those capable of representing non-printable ASCII characters, can also cause problems.

If you want to use Windows fonts, the best advice is to stick to the symbologies that do encode individual characters and do not have complex start and stop code sequences. Probably the most popular symbology in this respect is Code 39 (see page 8). Often, however, Code 39 fonts don't allow check digits. It is worth finding a font that allows check digits to be built in, as without these, Code 39 can be susceptible to misreads.

Poor and incorrect use of fonts is probably now becoming one of the most common reasons for the apparent "failure" of bar codes to read. However, software packages are now becoming available that are specially designed to overcome these difficulties. Rather than function as labelling packages or just simple fonts, these packages know the rules about constructing valid bar codes. Once the software has designed the bar code it can simply be pasted into the main Windows application (via the Windows clipboard). More advanced users can also use these packages via Windows DDE to automate the process (such a package was used to produce the bar codes in this booklet).