Ink jet recording method and apparatus for preventing color boundary blur

Abstract

A head for discharging yellow ink, magenta ink, cyan ink and first black ink having a relatively fast penetration velocity to a recording medium and a head for discharging second black ink having a relatively low penetration velocity are used to print an image. When a black image is adjacent to a color image, the black image is formed by using the first black ink, and when the black image is not adjacent to the color image, the black image is formed by using the second black ink. A black ink and a plurality of color inks having a different penetration velocity to a recording medium than that of the black ink are also used to print an image. Whether a color image area is present in the vicinity of a black image area of record data or not is determined, and whether the black image area is to be formed by the black ink or by the color inks is decided in accordance with the determination result, and when the black image is to be formed by the color inks, the color inks are used based on a mask pattern pseudo-randomly prepared to make the change in tonality less recognizable.