1. A printing device for printing on a print medium while performing main scanning, comprising: a print head having a plurality of nozzles ejecting a same given ink and a plurality of eject drive elements for causing droplets of ink to be ejected from the plurality of nozzles; a main scan drive section for performing main scanning by means of moving the print medium and/or the print head; a sub scan drive section performing sub scanning by means of moving the print medium and/or the print head; a head drive section for providing a drive signal to each eject drive element in response to a print signal; and a controller for controlling the sections; the controller having a first print mode wherein gradation reproduction with the same ink is performed by: (i) designating as a unit of gradation reproduction a group of N contiguous pixels arranged in a selected one of a main scan direction and a sub scan direction where N is an integer of at lease 2; (ii) setting a volume of ink ejectable onto at least one pixel location of the N pixels to a value different from a volume of ink ejectable onto other pixel locations; and (iii) controlling the volume of ink at each pixel location of the N pixels to reproduce M gradation levels for each group of the N pixels where M is an integer of at least N&plus;2.