Abstract: A method of developing electrostatic images in which a liquid developer is maintained in quiescent condition in contact with the base material carrying the electrostatic image and wherein the developer contains in separate coexistence within an insulating carrier liquid toner particles of relatively low dielectric constant and movement-inducing particles having a high dielectric constant. The presence of both sets of particles results in agitation in the liquid due to particle movement in a field by charge exchange between the high dielectric particles and the other particles to produce random agitation of the particles in the liquid and thereby high mobility of the toner particles during developing.

Abstract: A method of printing comprising applying a conductive developer to a imaged dielectric surface in the presence of an energising electrical image-defining field to form a master having conductive and relatively insulating areas defining the image, inking the said surface in the presence of a field of a polarity to urge the ink on to the surface to retain it at the relatively insulating image areas, and transferring the ink from the said surface to a receiving surface in the presence of a field of a polarity to urge the ink on to the receiving surface, and continuing inking the said master and transferring the ink to further receiving sheets.