A positive-working electrostatic liquid developer consisting essentially of (A) a nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount;(B) thermoplastic resin particles having dispersed therein a quaternary ammonium compound which is substantially insoluble in the nonpolar liquid and is represented by the general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 may be the same or different and are hydrogen, alkyl of 1 to 40 carbon atoms, aryl of 6 to 30 carbon atoms, and any of the group R.sub.1, R.sub.2, R.sub.3, and R.sub.4 may be joined to form a 5 or 6 membered ring, and A.sup.- is an anion; and (C) a nonpolar liquid soluble ionic or zwitterionic charge director compound. The process of preparation of the electrostatic liquid developer is described. The liquid developers are useful in copying, color proofing including digital color proofing, lithographic printing plates and resists.