The application relates to a method of producing an electrostatic ink composition, the method comprising: mixing a resin and a conductive pigment in a continuous mixer to form a compounded mixture comprising particles comprising the resin and the pigment; adding a liquid carrier to the compounded mixture, such that the particles comprising the resin and the conductive pigment are dispersed in the liquid carrier; and, before, during or after adding the liquid carrier to the compounded mixture: imparting a charge on the particles comprising the resin and the pigment.