Thermal transfer printing is a flexible tactual direct-marking method in which a thermal printing head with a freely programmable matrix of small heating elements transfers the print image to the back of an ink ribbon. The color upon the ribbon then melts locally and is transferred to the workpiece. In addition to flat surfaces, cylindrical surfaces or other geometries such as cables or writing instruments can be printed as well. Thermal printing heads are furthermore suitable for marking thermo-sensitive special papers or thermal labels that change color when heated. The printing process can produce colored and very high-contrast permanent markings, which, however, are not heat-resistant. Important areas of application are marking with barcodes or 2D codes, fonts, consecutive numbers and graphics on cardboard packaging, plastics, painted metals and wood surfaces. Typical products are folding boxes, plastic enclosures or security labels.
