The invention provides printing method of printing on a printing medium. The method includes: generating dot data representing a status of dot formation on each of print pixels of a print image to be formed on the print medium, by performing a halftone process on image data representing a input tone value of each of pixels constituting an original image; and generating the print image with a print head by mutually combining a plurality dot groups in a common print area, each of the plurality dot groups being formed in each scan of the print head in response to the dot data. The generating dot data comprise setting a condition for the halftone process for reducing contact between dot groups formed consecutively by a plurality of temporally consecutive scan within at least part of tone values.