A wet grinding process is used in which the dye particles or pigments are comminuted in suspensions or dispersions down to a few micro- and in some cases nanometers. The beads are the aiding means in the bead mill for transferring the mechanical energy to the particles to be comminuted. Only by adjusting the size of the dye particles, paints or varnishes obtain their desired properties such as opacity, colour strength, brilliance or durability.