Data Technologies, Inc.

Bar Code Tutorial: Printing

Bar codes can be printed using standard printers, or special bar code printers available from major manufacturers. We are all fairly familiar with standard printers, and their capabilities. Bar code printers are often most suitable to the task of printing large quantities of labels, because they differ from standard printers in a couple ways:

Many bar code printers are field-oriented. Basically, you download a format to the printer telling the printer where each field is located on the label, and how it is to be printed. As an example, you might tell it that

• the first field is printed in code 39 bar code, 1/2" high starting in the upper-left corner of the label.
• the second field is printed in human-readable text just below the bar code.

After the format is loaded into the printer, you can print a label just by sending the actual text to print (there is no need to resend the format information.) Standard windows printers require that each label be printed by sending the formatting data every time, along with the data to print. When you are printing thousands of labels, the time savings can be significant.

In addition, bar code printers are designed to print labels. They can strip the backing from labels automatically, and are more rugged for high use situations. Finally, these printers usually use thermal printing technologies which can result in higher-density bar codes.

With that background, there are four basic ways to print bar codes.

• bar code fonts
• print drivers
• custom programs
• integrated solutions

Bar code fonts

Bar code fonts for Windows are available from many vendors. These allow you to print bar codes on your Windows printer just the same way as you would print any other font. It can be very useful in document tracking, for example, where the entire document could be composed in your word processor, with the tracking number entered right in the document in a bar code font.

Bar code fonts, however, do not work with most standard bar code printers. In addition, not all bar code symbologies are available, because some of them do not translate into the font model. These bar codes are compressed in some manner so a given letter does not translate into a fixed sequence of bars.

Where you wish to imbed a bar code or bar codes into standard documents, bar code fonts are the method of choice. We use bar code fonts in our manuals.

Print drivers

Print drivers for Windows are available for certain bar code printers. When installed, you can print right to the bar code printer like you would any other printer. Quite of bit of magic has been done to make this system work, and when it does work, the results can be great. However, common complaints seem to be slow printing and occasional bugs. We recommend that you be sure to test the driver before committing to using it.

Custom programs

If you have control over the source code for your program, you can modify it to print the bar code directly to the bar code printer. This is usually the second best method to use when available (integrated solutions when available are usually better.) Communication with the printer is somewhat complex, but not overwhelming. Our program DDEPrint was written to make that communication chore easier.

Integrated solutions

If you have an existing database, MRP system, or other system that you are contemplating adding bar code to, you should check to see if they already have a bar coding printing module that can be purchased. If they do, it is usually best to just purchase the module. The only reason you might want to choose another option in this case, is if the module does not support a bar code printer that you require.