Patent ID: 7297194

Claim:
Ink jet ink comprising at least water, a colorant, a water-soluble organic compound 1 and a water-soluble organic compound 2 , wherein a viscosity of the ink jet ink is 1 to 5 cps at 25° C., the water content (%) is 77 mass % or less based on the total amount of the ink jet ink, the content Y(%) of the water-soluble organic compound 2 is Y<15 mass %, and the content X(%) of the water-soluble organic compound 1 is 10 mass % or more based on the total amount of the ink jet ink and the content X(%) of the water-soluble organic compound 1 and the content Y(%) of the water-soluble organic compound 2 based on the total amount of the ink jet ink satisfy the relation of the following formula (I) and formula (II): 0.15≦Y/X≦0.9, (I) X+Y≧ 15 mass %, (II) and wherein the water-soluble organic compound 1 is a water-retentive, water-soluble organic compound having a difference between the water retention ability in an environment of a temperature of 23° C. and a humidity of 45% and the water retention ability in an environment of a temperature of 30° C. and a humidity of 80% of 36% or less, and the water-soluble organic compound 2 is a water-soluble organic compound other than the colorant and the water-soluble organic compound 1 .