Abstract: Improved process for the preparation of copper phthalocyanine pigment stable to crystallization by grinding a crude copperphthalocyanine and adding a compound stabilizing the pigment against crystallization and derived from phthalocyanine, wherein the improvement comprises dry grinding the crude phthalocyanine in the absence of any mineral substrate and of any crystallizing solvent thereby obtaining a ground phthalocyanine of non-pigmentary or feebly pigmentary character, and treating the said ground phthalocycanine with a crystallizing solvent in the presence of the stabilizing compound at a temperature from ordinary room temperature to the boiling temperature of the solvent, the concentration of the stabilizing compound being from 1% to 25% of the weight of the phthalocyanine; pigmentary compositions in the form of powder or pigmented paste obtained by such a process and compositions containing a stable copper phthalocyanine pigment prepared in accordance with such a process.