The core element of a thermotransfer printer is the thermal print head, which contains many individual heating points, called 'dots', in a row. The thermal transfer ribbon is used as an ink carrier. It is comparable to the carbon ribbon on a typewriter. The difference is that, during thermal transfer printing, the colour is not transferred mechanically, but thermally. When heating the individual dots of the thermal print head, the ink is melted onto the thermal transfer ribbon and remains stuck to the film.