A cartridge that holds physical print medium materials for a modern laser printer. Rather than containing wet ink, a toner cartridge has toner powder inside that is used to form text and graphics on a page through an electronically charged and heated printing process.

A thermal printer uses heat to transfer an impression onto paper. There are thermal wax transfer printers which adhere a wax-based ink onto paper. More commonly there are direct thermal printers which print the image by burning dots onto coated paper when the paper pases ofer the heating elements. This printer is mostly used for point of sale systems.

Toner is a dry powdery substance used in laser printers and photocopiers which forms the text and images on the printed paper. In its early form it was simply carbon powder. In order to improve the quality of the printout the individual carbon particles were blended in a polymer. The polymer particles can be melted by the heat of the fuser, causing it to bind to the fibers in the paper. The exact polymer varies by manufacturer but might be a Styrene Acrylate Copolymer or a Polyester Resin. Typically, you can print thousands of pages with a single cartridge.