A printing device includes a nozzle row for chromatic ink comprising K nozzles and a nozzle row for achromatic ink comprising (n·K) nozzles. In a color region, an image-forming operation is performed m times in which the movement direction of the nozzle rows switches alternately between forward and reverse directions, whereby a region of the image having a predetermined width is formed. The image-forming operation performed m times includes the image-forming operation performed once in which both of the nozzle rows for chromatic ink and for achromatic ink are used, and the image-forming operation performed (m−1) times in which only the nozzle row for chromatic ink is used. In a monochrome region, the image-forming operation is performed once in which only the nozzle row for achromatic ink is used, whereby a region of the image having a predetermined width is formed.