An all-inkjet-printed organic thin film transistor (OTFT) with a double-layer dielectric structure is proposed and implemented in this study. By using the double-layer structure with different dielectric materials (i.e., polyvinylphenol with poly(vinylidene fluoride-co-hexafluoropropylene)), the threshold-voltage of OTFT can be adjusted. The threshold-voltage shift can be controlled by changing the composition of dielectric layers. That is, an enhancement-mode OTFT can be converted to a depletion-mode OTFT by selectively printing additional dielectric layers to form a high-k/low-k double-layer structure. The printed OTFT has a carrier mobility of 5.0 x 10(-3) cm(2)/V-s. The threshold-voltages of the OTFTs ranged between -13 V and 10 V. This study demonstrates an additional design parameter for organic electronics manufactured using inkjet printing technology. (C) 2013 Elsevier B. V. All rights reserved.