Abstract: Electrographic apparatus, that is apparatus for obtaining electrical signals related to the movement of a point, such as a pen or stylus, over a pressure sensitive surface, and a method of producing an electrode surface for such apparatus. The pressure sensitive surface is formed by the upper surface of a taut flexible membrane. Two generally parallel electrode surfaces are formed by electrically conductive coatings on the lower surface of the flexible membrane and on an upper surface of a backing member so that pressure applied to the pressure sensitive surface locally interconnects the electrode surfaces. In use, voltages are applied orthogonally to the respective electrode surfaces so that the potentials developed at points on the surfaces correspond to the X and Y coordinates of those points.