A printing technology where ink is squirted through the air onto the surface to be printed. The ejection is typically by piezoelectric heads, which tolerate a wider range of inks, and the more proven (in high volume) boiling technology. Ink jet printing is used by Xerox, Plastic Logic and others for thin film transistor circuits and by CDT and others to make OLEDs. It is useful on surfaces that are not flat and it uses little ink with little waste and quite high definition but it is relatively slow.
See the IDTechEx report Introduction to Printed Electronics