Magenta dye, jet ink, and color set

A lightfast ink comprising at least 1 percent by weight of a dye dissolved in a polar vehicle, said dye being of the structural formula;

• ##STR18## wherein:
• X is ##STR19## R.sub.1 is:
• an aliphatic radical having from 7 to 18 carbon atoms;
• the radical ##STR20## in which R.sub.2 is -lower alkoxy, -halogen, --NO.sub.2 --CN, --CO.sub.2 H;
• R.sub.3 is --H, -lower alkyl having 1 to 4 C atoms, -halogen, --CO.sub.2 H;
• M is H, Li, Na, K, --N(R.sub.4).sub.4 in which
• R.sub.4 is H, ##STR21## in which R.sub.5 is --H, -lower alkyl, and
• .sub.n is 1 to 4;
• and in which
• one of the --SO.sub.3 M groups on the amino-naphthol radical is positioned meta or para to the --NH-- group and the other --SO.sub.3 M is meta to the --OH.

A set of inks comprising a magenta ink, a cyan ink and a yellow ink,

• said magenta ink comprising a magenta dye of the structure formula:
• ##STR25## wherein:
• X is ##STR26## R.sub.1 is:
• an aliphatic radical having from 1 to 18 carbon atoms;
• the radical ##STR27## in which R.sub.2 is --H, -lower alkyl of 1 to 4 C atoms, -lower alkoxy, -halogen, --NO.sub.2 --CN, --CO.sub.2 H;
• R.sub.3 is --H, -lower alkyl having 1 to 4 C atoms, -halogen, --CO.sub.2 H;
• M is H, Li, Na, K, --N(R.sub.4).sub.4 in which
• R.sub.4 is H, ##STR28## in which R.sub.5 is --H, -lower alkyl, and
• .sub.n is 1 to 4;
• and in which
• one of the --SO.sub.3 M groups on the amino-naphthol radical is positioned meta or para to the --NH-- group and the other --SO.sub.3 M is meta to the --OH
• dissolved in a polar solvent,
• said cyan ink comprising Direct Blue 199 dissolved in a polar solvent, and
• said yellow in comprising Direct Yellow 132 dissolved in a polar solvent.