Abstract: There is provided an aqueous ink jet ink composition suitable for use in continuous ink jet printers comprising: (a) a surface modified carbon black pigment; (b) at least one organic pigment; and (c) an aqueous carrier medium. The black aqueous pigment ink formulated in accordance with this composition provides a dried ink film whereof the resistivity is increased to a level whereby no printer failure or print defects are caused by electrical shorts when the printer has been out of use for a sufficient time to allow the ink to dry out in parts of the apparatus. The ink may also comprise at least one dispersant for the organic pigment.

Abstract: There is provided an aqueous ink jet ink composition suitable for use in continuous ink jet printers comprising:

Abstract: There is provided a pigmented aqueous ink set including: (a) A concentrated black ink having a pigment concentration up to 10% by weight; and (b) at least one dilute ink having a pigment concentration below that of the concentrated ink; wherein all the inks additionally includes an aqueous carrier medium and at least one of the set of inks includes a combination of carbon black and Pigment Blue 60.

Abstract: A pigmented aqueous ink jet ink composition is provided which comprises a sarcosinate compound of the formula: R—CO—NMe—CH2—COOM In which R is a ballasting group comprising at least ten carbon atoms and M is hydrogen, an alkali metal cation, an ammonium cation or a substituted ammonium cation. Preferably the ink is prepared by dispersing the pigment in the presence of the sarcosinate compound in water, together with optional co-solvents or other components, and then diluting this dispersion to form the ink.

Abstract: There is provided a pigmented aqueous ink set which comprises: (a) a cyan ink which comprises at least one pigment which is a phthalocyanine compound; (b) a magenta ink which comprises at least one pigment which is a quinacridone compound; (c) a yellow ink wherein the pigment is C.I. Pigment Yellow 155; (d) a green ink wherein the pigment is selected from the group consisting of C.I. Pigment Green 7, 36, and mixtures thereof; (e) an orange ink wherein the pigment is selected from the group consisting of C.I. Pigment Orange 34, 36, 43, 61, 64, 71, and mixtures thereof; together with optionally (f) a black ink which comprises a black pigment. Preferably there is also present at least one water soluble organic cosolvent. The pigmented ink set is suitable for use in ink jet printing.

Abstract: There is provided a pigmented aqueous ink set comprising:—

Abstract: There is provided a pigmented aqueous ink set which comprises: