| abstract |
An ink-jet ink composition comprising: a pigment, a polymer pigment dispersion, polymer particles, a hydrophilic organic solvent, water, and at least one of a water-soluble acidic compound having a molecular weight of 200 or less or a salt thereof in an amount of from 50 ppm to 1,000 ppm; an ink set that includes the ink-jet ink composition and a treatment liquid that forms an aggregate when contacted with the ink-jet ink composition; and an image forming method using the ink set. |