Bar code printers are used to output bar codes in printed form. They differ in terms of performance specifications and bar code symbology. Printing width, printing rate, and resolution are important performance specifications to consider when selecting bar code printers. Bar code symbologies are machine-readable representations of information stored in bars and lines.  Choices include: Bookland EAN, Codabar, Codablock, Code 1, Code 11, Code 128, Code 16K, Code 39, Code 49, Code 93, European article numbering (EAN), Japanese article numbering (JAN), Industrial 2 of 5, Matrix 2 of 5, Standard 2 of 5, interleaved 2 of 5, LOGMARS, MaxiCode, Plessey, PDF417, PLANET, POSTNET, SISAC, Telepen, UPC, Vericode and DataMatrix. Bar code printers that print composite symbologies are also available. 

Bar code printers use daisy-wheel, screen printer, direct thermal, thermal transfer, ink jet, laser, LED, LCD, letterpress, rotary press, rotogravure and dot matrix technologies. Daisy-wheel printers use a small wheel with a single pin for each character. Screen printers transfers an image onto a mesh screen by blocking out the surrounding area. Letterpress printers are simple printing presses that use a die with raised type to press text onto the page. Rotary presses are similar to letterpresses, but place the raised type on a roller instead of a flat die. Rotogravure printers use photographic techniques to produce the plate used for printing. Direct thermal use heat to set images on non-curling, smudge-proof, heavy-stock thermal paper. By contrast, thermal transfer uses heat and pressure to transfer resin-based ink from tiny ribbons directly onto the paper. Ink jet printers spray ink droplets through a nozzle onto the page. There are two basic types of ink jet printers: thermal and piezo. Laser printers use a laser beam to produce an image on a drum. LED bar code printers and LCD bar code printers are similar to a laser printers, but uses light-emitting diodes (LED) or liquid crystal displays (LCD) to produce an image on the drum. 

Bar code printers include equipment for flexographic printing and hot stamping, as well as line printers, offset printers, pad printers, and computer plotters. Flexography is a rotary-press printing technology that uses water-based inks. Flexographic printers are often used to print on plastic, paper or cardboard. Hot stamping machines use heat and pressure to apply an image onto a surface from a film that carries a thin leaf of color. Line printers contain a chain of characters or pins that print an entire line at one time. They are very fast, but produce low-quality print. Offset printers use a rubber cylinder to transfer an inked image from a printing plate to paper or other media. Pad printers use silicone pads to print on contoured or difficult plastic surfaces. They are used for relatively small images, text and graphics. Plotters are bar code printers that use a pen to produce line art and images on paper or other media.  

Some bar code printers are designed to handle single-sheet, fan-fold, or corrugated paper. Others can print on glass, metals, plastics, electronics, semiconductors, wood, or fabrics. Bar code printers with a serial, parallel, Ethernet, or other digital interface can be integrated with front-end office equipment and personal computers (PCs). Printers that output signals according to industrial fieldbus protocols are also available. In terms of features, bar code printers may provide color printing, copying or scanning capabilities; integral memory for data storage; application software; and cutters for continuous forms, rolls, or webs. Bar code printers that are sold in Europe should meet the Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronics Equipment (WEEE) directives from the European Union (EU).