Risograph also known as RISO printing is a high-speed, photocopier meets mimeograph printing system, named after the manufacturer, Riso Kagaku Corp. It was invented for high volume copying and printing back in mid 80s. Master sheets transfer the ink from the drum onto the passing paper according to the design that has been scanned in or entered digitally. The artwork is transferred onto the master sheet by a series of heated spots on a thermal plate which burn away the artwork shape leaving voids in the master. Every print using this master will be the same colour. Changing colour requires removing and replacing the interchangeable ink drum and creating a new master to wrap around that drum. This method of printing is a more affordable process than screen printing or offset lithography so is often used for zines and comics, yet it can achieve similar aesthetics and beautiful colour overlays.