In this paper, we describe our fabrication of a solution-processed organic thin-film transistor (OTFT) with 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) as the organic semiconductor (OSC) and methyl-siloxane-based spin-on glass (SOG) as the inorganic gate dielectric. Also, we compare these results with OTFTs using different substrates such as a silicon wafer or a polyethersulfone (PES) substrate. From electrical measurements, we observed exemplary I-V characteristics for these TFTs. We calculated the field effect mobility to be 0.007 cm(2)/V s for an OTFT fabricated on a wafer and 0.004 cm(2)/V s for an OTFT fabricated on a PES substrate. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.