The best way to print bar codes is to use laser, ink jet or dot matrix printers. Bar code printers are of two major types.

A bar code direct thermal printer uses heat to print the images. This printer burns dots on heat-responsive paper. The images printed using this technology are susceptible to heat, industrial ultraviolet light, sunlight, and pressure. These labels are best suited for short-life purposes, and they are quite liable to worsen over time. It is best not to use direct thermal printing for long-life applications.

A bar code thermal transfer printer is another label printer that prints images through the use of heat. It melts the ink in the ink ribbon on a wide range of synthetic material labels and paper. An extensive range of ribbon and media formulations is obtainable, giving the facility to print bar code labels for almost any application. Those may include extreme environment and long-life applications.

Direct thermal printers are characteristically more affordable than thermal transfer printers, as they do not require the mechanisms and electronics that are necessary to control and run an ink ribbon.

Direct thermal and thermal transfer printers typically require print software and "optional" bar code label designs. The most popular bar code printer is the archetypal HP compatible laser printer. Laser printer resolution is generally of higher quality than industrial bar code printers.

It is risky to print bar codes with colored ink or colored paper. Colored ink and colored paper have the propensity to diminish the contrast between the spaces and bars. It is vital to remember that most scanners use red light. Thus, if you print the bars with any shade of red, there is a likelihood of the light reflecting off the bars as white spaces. Also, avoid printing black bars on colored paper.