Patent ID: 6939399

Claim:
An ink set comprising a yellow ink containing at least one yellow dye, a magenta ink containing at least one magenta dye, and a cyan ink containing at least one water-soluble cyan dye, wherein an oxidation potential of the magenta dye and an oxidation potential of the cyan dye are each higher than 0.8 V (vs SCE), wherein the cyan dye is represented by the following general formula (C-I), and the magenta dye and the yellow dye are represented by the following general formula (MY): wherein in General Formula (C-I), X 1 , X 2 , X 3 and X 4 each independently represents an electron-withdrawing group having a σp value of no less than 0.40; Y 1 , Y 2 , Y 3 and Y 4 each independently represents a monovalent substituent; M represents a hydrogen atom, a metal element or an oxide, hydroxide or halide thereof; a 1 to a 4 and b 1 to b 4 , respectively represent a number of substituents of X 1 to X 4 and Y 1 to Y 4 ; a 1 to a 4 and b 1 to b 4 each independently represents an integer from 0 to 4; a sum of a 1 to a 4 is no less than 2; and an ionic hydrophilic group is disposed as a substituent at any position on X 1 , X 2 , X 3 , X 4 , Y 1 , Y 2 , Y 3 and Y 4 ; General Formula (MY) A—N═N—B wherein in General Formula (MY), A and B each independently represents a substituted aryl group or a substituted or non-substituted 5-membered or 6-membered unsaturated heterocyclic group, at least one of A and B represents a heterocyclic group having a substituent including an electron withdrawing group or represents an aryl group having an —NH—R group at a para-position, and R represents a substituent.