Process black ink compositions and uses thereof

A method of preparing a process black ink composition, the method comprising:

• a) providing a cyan colorant comprising a cyan pigment, a magenta colorant comprising a magenta pigment and a yellow colorant comprising a yellow pigment, wherein a ratio of the cyan colorant to the yellow colorant is 0.70-0.80:1.0 and a ratio of the magenta colorant to the yellow colorant is 0.90-0.80:1.0,
• b) acoustically mixing the colorants;
• c) acoustically mixing a photo-initiator;
• a dispersant and at least one curable ink vehicle component selected from the group consisting of a monomer and an oligomer with the acoustically mixed colorants to form a curable ink mixture,
• d) milling the curable ink mixture formed in c) to obtain a process black ink composition, wherein the process black ink composition does not comprise carbon black.

A method of halftone printing, the method comprising:

• providing a cyan ink composition, a magenta ink composition and a yellow ink composition,
• applying the cyan ink composition, the magenta ink composition and the yellow ink composition onto a re-imageable imaging member surface, wherein a ratio of the cyan ink composition to the yellow ink composition is 0.70-0.80:1.0 and a ratio of the magenta ink composition to the yellow ink composition is 0.90-0.80:1.0;
• forming an ink image;
• transferring the ink image from the re-imageable surface of the imaging member onto a printable substrate to form a halftone black image;
• wherein the halftone black image does not comprise carbon black,
• wherein the cyan ink composition comprises at least about 15% by weight of a cyan pigment, the magenta ink composition comprises at least about 15% by weight of a magenta pigment and the yellow ink composition comprises at least about 15% by weight of a yellow pigment,
• and wherein said cyan ink composition, said magenta ink composition and said yellow ink composition each further comprises:
• a photo-initiator,
• a dispersant, and
• a curable ink vehicle component comprising at least one component selected from the group consisting of a curable monomer and a curable oligomer.