Image permanence device

摘要

A method and apparatus for preventing smudging of indicia printed on a surface by selective application of an amount of coating material to lubricate the contact with surfaces abrading the printed indicia or to provide physical separation from abrading surfaces, and thus prevent smearing. The coating material is preferably a "Teflon" micropowder that is applied by using impulse devices to dispense controlled amounts of the micropowder from a container, with the dispensed micropowder being transferred to, and passing through a plurality of apertures adjacent the surface of a piece of paper on which indicia has just been printed by a nonimpact printer such as a laser printer.