Use of metal complexes of hydrazones as pigments

A process for pigmenting high-molecular organic material, which comprises

• incorporating therein a preformed transition-metal complex of a monohydrazone of the formula I ##STR68## wherein A is an isocyclic or heterocyclic aromatic radical, B is a radical selected from the group consisting of unsubstituted or mono- or disubstituted benzene, naththalene, pyridine, pyrimidine, pyrazolone, quinoline, isoquinoline, pyrazole or coumarin where the substituents are halogen, C.sub.1 -C.sub.6 -alkyl, C.sub.1 -C.sub.6 -alkoxy, cyano, nitro, carboxy, C.sub.2 -C.sub.7 -alkoxycarbonyl, carbamoyl, phenyl, phenoxy, phenylcarbamoyl, benzoylamino, or phenyl, phenoxy, phenylcarbamoyl or benzoylamino each substituted by halogen, C.sub.1 -C.sub.6 -alkyl or C.sub.1 -C.sub.6 -alkoxy, and D is hydrogen, or if B is a phenyl or naphthyl group, D is hydrogen, or a carbonyl group which together with the structural element ##STR69## forms a phthalimide or naphthalimide group.