Thermal Printing

To apply images onto a blank plastic ID card, most ID badge printers use either dye sublimation or thermal transfer printing. Both processes use a thermal printhead to heat an ID card printer ribbon. Printheads used during the thermal transfer process heat (and melt) ink, while printheads used during dye-sublimation printing heat and vaporize dye.

Frequently an ID card printer and the ribbon it uses combine both technologies. This is most commonly used to produce a dense black color. While combining the colors cyan, magenta, and yellow – the dyes used in dye sublimation printing - do produce the color black, it is a sad, grayish black. More importantly, this black contains no carbon because it is made from dye, rather than ink and is therefore invisible to some bar code scanners.