A multi-color printer includes a plurality of print cartridges and a frame. Each print cartridge corresponds to a different color to be printed, and includes a keying feature different from the other print cartridges. The frame defines a plurality of docking stations, with each docking station including...http://www.google.com/patents/US20020094208?utm_source=gb-gplus-sharePatent US20020094208 - Multi-color printer with keyed print cartridges
