Abstract: An imprinter having a roller platen assembly movably mounted on a head member for imprinting data from a printing plate such as a credit card onto a form positioned over the plate. The roller platen assembly has a reciprocally driven carriage means containing at least one removably mounted cartridge containing at least one row of roller platens mounted therein in parallel, spaced apart relationship to each other. A plurality of backup rollers are rotatably mounted within said roller platen assembly, each in contact and vertical alignment with each of the platen rollers when the cartridge means is in position within the carriage means. At least one of the roller platens is in contact with the raised printing elements of the printing plate at all times during each printing cycle of the imprinter to thereby lessen any tendency for smudging of the form to occur.