The discovery of (semi) conducting polymers opened a route to the fabrication of microelectronics by printing. We designed structural and electrical properties of printed polymeric thin films and multilayers to set up field-effect transistors. The polymeric transistors are fully logic capable as is proven by persistent operation of an integrated ring-oscillator circuit. Solution processing of the polymers in printing is completely done under ambient conditions resulting in stable operation of the printed transistors and microcircuits. (C) 2004 American Institute of Physics.