Patent ID: 7204873

Claim:
A neutral black ink for ink-jet printing, comprising: an ink vehicle; carbon black; cyan pigment; and magenta pigment; wherein an absorbance ratio of carbon black: cyan pigment: magenta pigment for the neutral black ink is 0.18:0.08:0.05 with values being measured at 1/5K dilution, 400–700 wavelength and each ratio value ranging +/−25%; wherein the carbon black, cyan pigment and magenta pigment are associated with a polymer or polymers which render the carbon black, cyan pigment and magenta pigment dispersible in aqueous solution; and wherein the neutral black ink is configured to be printed with an ink selected from a neutral medium gray ink, a neutral light gray ink, a neutral dark gray ink, and combinations thereof, each of the gray inks including a predetermined combination of carbon black, cyan pigment, and magenta pigment.