To provide a printer suppressing graininess of a background.

First image data in which each pixel has a recording ratio of white ink dots and at least one second image data in which each pixel has a recording ratio of nonwhite ink dots are acquired. In generating first halftone data and second halftone data indicating whether or not each pixel at least records dots based on the first image data and the second image data, the first halftone data and the second halftone data are generated so that the white ink dots are overlapped with the nonwhite ink dots on a printing medium, and based on the first halftone data and the second halftone data, the white ink dots and the nonwhite ink dots are recorded on the printing medium.