Abstract: A master card for use in a hectographic printing machine, comprises two layers of snythetic plastics material, having respective apertures therein which are aligned with each other to form a window, and a layer of carbon-receiving material between the synthetic plastics layers and closing the window. The card has an information-carrying zone including opaque areas into which holes can be punched to form transparent areas arranged in predetermined positions to provide information readable by light transmission, and a strip of magnetic material which is machine programmable by magnetization and machine readable.