Inter Mac maccell T-3 + applies a new DOD technology to print on a wide range of substrates. The print heads of these printers contain a series of chambers that are filled with ink. By applying voltages to the walls of these chambers, a distortion is caused that bows the walls outwards. This distortion causes the ink pressure to drop, drawing more ink into the chamber. When the voltage is released and the walls return to their original positions, an ink droplet is expelled through each selected print nozzle.