The present invention relates to a method of preparing a polymer modified pigment comprising the steps of, combining, in any order, a modified pigment comprising a pigment having attached at least one reactive group, a polymer comprising at least one functional group, and a non-reactive diluent, to form a reaction mixture, reacting the polymer and the modified pigment in the reaction mixture to form a mixture comprising the polymer modified pigment and the non-reactive diluent; and removing the non-reactive diluent from the mixture to form the polymer modified pigment. Also disclosed are the resulting polymer modified pigments and inkjet ink compositions comprising them.