In a laser printer, paper is given an electro-static charge by passing it over a charged drum and then a laser scans it discharging all clear areas. Next the paper is passed over a tray of powdered ink (toner) which is attracted to the charged areas. Finally the ink is bonded to the paper by heat or pressure. Laser printers are quiet and are used for high quality low or high volume work. We have a number in the department including PS9 (a Postscript printer near 615) and PS4 (a double sided Postscript printer outside room 663).