A method for dispersing a pigment in a solvent comprises mixing the pigment in a nanoscale 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.