Process for the preparation of fluorescent compositions, fluorescent compositions and their use

A composition obtained by

• (1) mixing a host chromophore and a fluorescing effective amount of a pigment precursor in a solvent, then generating a pigment as guest chromophore in-situ from the pigment precursor, and, subsequently, isolating the mixture of the host and guest chromophores thereby forming a solid solution, or
• (2) mixing a polymer as a matrix or a polymer precursor and a pigment precursor in a solvent, in the presence of a chromophore being a host component, then generating a pigment in-situ from the pigment precursor, and, subsequently, isolating the mixture of polymer and pigment, and the host component, thereby forming a solid solution, wherein the absorption spectrum of the pigment (guest chromophore) overlaps with the fluorescence emission spectrum of the host chromophore, wherein the pigment is selected from the group consisting of quinacridones, anthraquinones, perylenes, indigos, quinophthalones, isoindolinones, phthalocyanines, diketo- and dithioketopyrrolopyrroles, and azo pigments, and wherein the host chromophore is selected from the group consisting of fluorescent anthracenes, oxazoles, pyrenes, coumarines, fluoresceines, rhodamines, perylenes, perinones, isoindolones and metal complexes consisting of metals and organic ligands.