Female Speaker: Xerography is based on the principle that has certain material can retain at electrostatic imprint of a brightly led image. When a document is placed in copier, a bright light is bounced off the paper through the lens and on to specially coated drum. The coating becomes electrostatically charged with a mirror image of the document. As the drum rotates, the fine black particles that make big ink called toner are attracted to the charged areas on the drum; the same areas that would be the print on the paper. As copy paper is rolled over the drum, a heat roller fuses the toner from the drum and on to the paper reproducing the original image.