1. An apparatus for printing graphical information on a surface, the apparatus comprising: a printhead for printing on the surface; an image sensor for recording an image of the surface, wherein the surface contains a position-coding pattern that identifies a position on the surface; and a processor for determining the position of the apparatus using the recorded image, wherein, for at least one predetermined position, the printhead prints onto the surface in accordance with a predetermined attribute, said attribute being associated with said predetermined position.