A process for the preparation of pigments of high purity which comprises reacting in the presence of an organic solvent an appropriate impure pigment with an organic acid of the formula R-X, or comprises reacting an appropriate impure pigment with an organic acid of the formula R-X, and subsequently adding an organic solvent to the resulting organic mixture, adding a precipitating agent to the resulting solution mixture, followed by separation of the desired pure pigment from the reaction mixture, wherein R is an alkyl group, containing from about 4 carbon atoms to about 22 carbon atoms, or an aryl group containing from about 6 carbon atoms to about 24 carbon atoms, and X is a group capable of yielding anions.