Toner for a printer is supplied in a toner cartridge. It is generally made of plastic and pigment, supplied with an electrical charge, which is essential to its function. When printing, the drum starts off with a positive charge, and then the printer uses a beam to discharge various spots on the surface of the drum, which creates an electrostatic image onto the surface. Finally, the toner coats the surface of the drum, and the paper picks up the image.