Patent ID: 8820909

Claim:
A black ink composition comprising a resin-coated carbon black containing a water-soluble resin and carbon black, a water-soluble polymerizable compound, a polymerization initiator, and water, wherein an average primary particle diameter of the carbon black is 20 nm or more, and an absorbance ratio of absorbance at a wavelength of 350 nm with respect to absorbance at a wavelength of 600 nm (absorbance at a wavelength of 350 nm/absorbance at a wavelength of 600 nm), when the black ink composition is diluted 5,000-fold with water, is 1.9 or lower, and the absorbance at a wavelength of 350 nm when the black ink composition is diluted 5,000-fold with water is from 0.3 to 0.46.