Patent ID: 7347890

Claim:
An ink set having four kinds of aqueous inks composed of the cyan ink, a magenta ink, a yellow ink, and a black ink, each ink comprising at least (a) water; (b) a water-insoluble coloring material; and (c) plurality of water-soluble organic solvents including (1) a good medium or good mediums for the water-insoluble coloring material and (2) a poor medium or poor mediums for the water-insoluble coloring material, wherein in the cyan ink, the ratio B 1 /A 1 is 0.5 or more and 3.0 or less, when A 1 denotes the total content (mass %) of the good medium in the cyan ink and B 1 denotes the total content (mass %) of the poor medium in the cyan ink; and wherein in the cyan ink, a water-soluble organic solvent showing a maximum Ka value out of respective Ka values of the plurality of water-soluble organic solvents as each determined by the Bristow method is the poor medium; and wherein for each aqueous ink in the ink set other than the cyan ink, the ratio B/A satisfies the following expression (I), when A denotes the total content (mass %) of the good medium or good mediums in the aqueous ink and B denotes the total content (mass %) of the poor medium or poor mediums in the aqueous ink: ( B 1 /A 1 )/( B/A )>1 (I).