Development of silver nanoparticle ink and printing process for printed circuits are presented. We have developed high performance silver nanoparticle ink that can sinter at very low temperatures. Silver nanoparticle ink was optimized for high-resolution inkjet printing system. A fully printed organic thin-film transistor was successfully fabricated using inkjet printing process. An excellent field effect mobility of 0.6 cm2⁄Vs was achieved using the developed silver nanoparticle ink.