Electrostatic Printing
It a printing technique done without any plate, ink or type form. The paper is covered with a thin layer of zinc oxide, making it an insulator in the dark and at the same time a conductor of electricity when exposed to light.
These machines are worn for printing of geographic maps. With the progression in technology and higher speed, the machines are also being used to print small books. Electrostatic printers are used for short run printing as they are faster and also do not cost much.