The most common barcode printers employ one of two different printing technologies. Direct thermal printers use a printhead to generate heat that causes a chemical reaction in specially designed paper that turns the paper black.

A barcode printer is a computer peripheral for printing barcode labels or tags that can be attached to, or printed directly on, physical objects. Barcode printers are commonly used to label cartons before shipment, or to label retail items with UPCs or EANs