An ultraviolet light absorbing polyester resin and toner particles incorporating such polymer are provided. The toner particles are particularly useful in photolithographic applications wherein ultraviolet light is used for making printing plates from color separation transparencies which contain imaged areas defined by the toner particles. The toner particles can be prepared, if desired, in finely divided form capable of forming high resolution electrographic images, and the toner particles can be used in dry or liquid developer formulation. The toner particles are heat fusible preferably at low temperatures, resist toner offset, and have good cohesivity.