The toner cartridge is a plastic reservoir which holds and dispenses toner to the printer drum. Toner is a powdery, dry ink which is attracted to the electrostatic charges on the drum. As the paper passes over the toner-treated drum, the particles are transferred to the page. Heated rollers then fuse the toner as the page is passed out of the printer to the output tray. Some toner cartridges also includes a small cleaning pad, which serve to wipe excess toner from the drum.
