Patent ID: 7101009

Claim:
A printing control method of generating print data to be supplied to a print unit to print, the print unit forming dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material, the printing control method comprising: (a) converting a pixel value representing color of each pixel in given image data into tone values of individual inks to express the color of the pixel with the quality-enhancing ink and at least part of the colored inks available in the print unit; and (b) generating dot data representing a dot formation state of a colored dot formed with the at least one colored ink and a transparent dot formed with the quality-enhancing ink in each pixel, according to the tone values of the individual inks generated by the color conversion, wherein the step (a) includes the step of determining whether the pixel value is equal to a characteristic value corresponding to a blank pixel where no colored dot is created, and setting a predetermined tone value to the tone value of the quality-enhancing ink when the pixel value is equal to the characteristic value, while converting the color conversion with reference to a color conversion table when the pixel value is other than the characteristic value, and the color conversion table maps the pixel value to a combination of the tone values of the individual inks to express the color of the pixel with the at least part of the colored inks and with the quality-enhancing ink.