The present inventions relates to An ink-jet printer for printing on an ediblesubstrate, the printer comprising a guide roller for guiding the substrate throughthe printer and a print head for printing on the substrate, the print head beingmounted adjacent the guide roller so as to be movable in a reciprocating mannersubstantially parallel to the guide roller characterised in that the print headmounts a roller cleaning apparatus which engages the guide roller as the printhead reciprocates. This prevents a build-up of residue from the edible substrateon the guide rollers, thus providing improved performance and reliability.A method of operating the printer in conjunction with a user terminal is also disclosed.
