According to OLEDNet, Seiko Epson developed a new OLED ink-jet printer head that can achieve a resolution of 360 PPI. This high-density print head uses two 180 PPI nozzles in 2 offset rows. The company managed to print prototype bottom-emitting and top-emitting OLED devices using this print head.
OLEDNet says that Seiko Epson is now aiming to develop a 600 PPI ink-jet printer head, by using two rows of 400 PPI nozzles.