In simplest terms, siderography is the means by which multiple images of the hand-engraved die are transferred to a printing plate.
In siderography, individually engraved elements such as the portrait, border, counters and text are first combined like pieces of a jigsaw puzzle to form one complete face or back of a note using a transfer press. Siderographers use this machine to exert as much as four tons per square inch to transfer the original work to a master die. Later, individual plastic molds are made from the master die and are assembled into one plate containing exact duplicates of the master die. Plate makers will then process this plate to create the metal printing plates that go on the presses.
After the dies are assembled and reproduced on plates, engravers cut in additional items, such as series, quadrant numbers, and signatures into the plates using a pantograph machine. A pantograph copies the die engraving onto the plate. As one part of the machine traces the original engraving another part engraves the image onto the new plate. The original engraved dies are stored and can be used again and again as needed.