ITO (tin doped indium oxide) coatings were produced by gravure printing process on PET and PEN foils. The printing paste consists of ITO nanoparticles, which are dispersed in a solvent and mixed with a binder. By modification of the printing paste, the sheet resistance (R/sq) of the ITO coatings after hardening under UV-irradiation at low temperatures (<130 degrees C) could be decreased to 1 k Omega/sq. R/sq could be further reduced down to 0.5 k Omega/sq by heat treatment under forming gas atmosphere (N-2/H-2), the transmission of the ITO coated foils still being more than 80% in the visible range. The application of these ITO films as a bottom electrode in organic photodiodes (OPDs) is shown, and the current density-voltage characteristics of the OPDs are presented. (C) 2009 Elsevier B.V. All rights reserved.