Patent ID: 8506067

Claim:
An ink jet image-forming method for forming an image by applying an ink in a fixed amount of from 0.5 pl or more to 6.0 pl or less to plain paper, wherein: the ink comprises a self-dispersion pigment, water, a water-soluble compound having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more as defined by the following equation (A) and a water-soluble compound having a coefficient of hydrophilicity-hydrophobicity of 0.25 or less as defined by the following equation (A), and has a surface tension of 34 mN/m or less, and wherein when an image having a portion where the ink is applied in a duty of 80% or more and in an amount of 5.0 μl/cm 2 or less in total is formed in a basic matrix for forming the image, the ink is divided and applied in plural stages, with the amount of the ink applied at each stage being 0.7 μl/cm 2 or less: Coefficient of hydrophilicity-hydrophobicity=[(Water activity value of a 20% aqueous solution)−(Molar fraction of water in the 20% aqueous solution)]/[1−(Molar fraction of water in the 20% aqueous solution)]. Equation (A)