An electrofax was a type of fax. It involved electrostatic printer and copier technology, where an image was formed directly on the paper, instead of first on a drum, then transferred to paper, as it would be in xerography. It was used in the United States from the 1950s through the 1980s. The paper used in this process was coated with a zinc oxide powder, adhered with a resin, to make it able to hold an electrostatic charge, and absorb toner, to form an image and allow the evaporation of toner dispersants. Users of electrofax machines purchased paper with the coating already applied.