Direct thermal printers use no ink, toner, or ribbon.
Direct thermal printing uses heat to selectively activate chemically treated, thermosensitive labels. The printer’s heated print-head comes in direct contact with the label, that has been coated with a material (a leuco dye) specially formulated to change color when exposed to heat. Once heated, the thermosensitive label reacts and darkens, creating the desired print.
As such, direct thermal printers use no ink, toner, or ribbon.
One important consideration when choosing this method is that the print is unstable and prone to fading over time, especially when stored in hot or humid conditions. Scratches can also produce enough heat to create marks on the label and affect the quality of the print.