A pigment is dispersed in a solvent by mixing the pigment nanoparticles with clay in a layered or platelet form and mixing the resultant mixture with the solvent. The method is based on geometric inhomogeneity and mutually exclusive aggregation. The layered or platelet clay having a high aspect ratio is provided to hinder aggregation of the pigment nanoparticles. The pigment nanoparticles can be stably dispersed in a matrix containing an organic solvent and water without aggregation again.