Communication: A low-cost method of producing nanostructured titania thick films is required if nanustructured titania is to be used to its full potential in applications in areas ranging from optics via solar energy to gas sensing. It is demonstrated that screen printing forms the basis of such a method, and the effect of annealing on the nanophase and the role of doping to prevent coarse-grain growth at relatively high temperature are discussed. Finally, miniaturized devices with deposited titania layers are shown to act as sensors for CO, their performance depending on the size of the grains.