A
pigment formulation comprising a) C.I.
Pigment Violet 23 of the formula (I) as base
pigment, b) a
perylenetetracarboxylic diimide compound that contains at least one sulfo group and is of the general formula (II) as
pigment synergist, in which: A is a bivalent >NR1 or >N-R2-SO3 -X+ radical, R1 is a
hydrogen atom or a C1-C30-
alkyl group, preferably a C1-C18-
alkyl group and especially a C1-C4-
alkyl group, or an
aryl group, preferably phenyl, where the
aryl group may be unsubstituted or mono- or polysubstituted by
halogen such as
chlorine or
bromine, sulfo, C1-C4-alkyl such as methyl or ethyl, C1-C4-alkoxy such as methoxy or ethoxy, or phenylazo, R2 is a straight-chain or branched C1-C6-alkylene group, especially
ethylene or propylene, X+ is NR3R4R5R6+ with R3, R4, R5, R6 = H, unbranched or branched C1-C30-alkyl, phenyl or phenyl-C1-C6-alkyl.