Patent ID: 8475578

Claim:
A magenta ink jet ink, comprising: (a) a magenta dye having the structure: wherein R 21 , R 23 , R 25 , R 27 R 29 , and R 31 are independently a hydrogen atom or sulfonate group; R 22 is a hydrogen atom or nitro group; R 26 and R 28 are independently a hydrogen atom or methyl group; R 24 and R 30 are independently a methyl or sulfonate group; and R 32 is a methyl or methoxy group; and (b) a second magenta dye having the structure: including potassium, sodium, lithium, and ammonium salts thereof; wherein the ink further includes calcium cations, magnesium cations, or a combination of calcium and magnesium cations at from about 1,000 ppm to 20,000 ppm.