Toner:

Toner is a powder mixture used in laser printers and photocopiers to form the printed text and images on the paper, in general through a toner cartridge. Mostly granulated plastic, early mixtures only added carbon powder and iron oxide, however, mixtures have since been developed containing polypropylene, fumed silica, and various minerals for triboelectrification. Toner using plant-derived plastic also exists as an alternative to petroleum plastic. Toner particles are melted by the heat of the fuser and are thus bonded to the paper. In earlier photocopiers, this low-cost carbon toner was poured by the user from a bottle into a reservoir in the machine. Later copiers, and laser printers from the first 1984 Hewlett-Packard LaserJet, feed directly from a sealed toner cartridge

Ribbon:

A printer ribbon is a spool of alternating colored dyes housed in a cartridge. Used in dye-sublimation printers, the four CMYK colors are used for each print. A CMYKO ribbon refers to CMYK plus the clear overlay used at the end. For ID card printers that print on both sides of the card, a CMYKOK ribbon is used, which prints black on the second side (last K in CMYKOK). See CMYK and dye-sublimation printer.

The paper comes into contact with the ink in the ribbon cartridge with the use of a spring on the printer head itself. Heat is essential to the thermal transfer printing process, and thus, when heat is applied onto the paper and the ink, the ink in the ribbon cartridge melts and sticks to the paper. This is how thermal transfer printing works.

The dot-matrix printers print images by striking tiny dots coming into contact with a cloth strip soaked in printer ink. Thermal printers used in cash machines, faxes, and similar devices use printer ribbons. The heat in the thermal printers melts the wax-like printer ink which then transfers to the paper.

Each print has its own set of CMYK colors on the ribbon. Unlike inkjet cartridges, which run out at different times depending on how much ink is used, printer ribbons have a fixed number of prints regardless of which colors dominate in the image.