Metallograph® Printed Electronics Conductive Thermal Transfer Ribbons for Printed Electronics and RFID Antennas – Available from SPF-Inc iimak’s Metallograph® thermal transfer conductive technology is a simple, fast and economical digital printing method for electronic circuits, sensors and RFID tag antennas. Aluminum and copper conductors are solid continuous metal, not printed particles. For UHF antennas the print direct to tag stock, bypassing the delays and costs of etching, and eliminating the need for inlays.