Abstract: A thermal printer and a control method for a thermal printer enable increasing throughput before a printing process starts by starting a duplex printing process without waiting to convert all print data into the front print buffer and back print buffer, enable executing a duplex printing process on a print medium without using a front print buffer and a separate back print buffer, and enable switching between simplex printing and duplex printing according to a specific command.

Abstract: A method for checking a correctness of impositions and correct mutual register of the print pages at a front side and a rear side of different types of printed matters using a check print apparatus comprising two co-operating printers. The method includes preparing impositions in a control unit of the front side and the rear side of a print original to be made, printing a plurality of print pages having a first imposition of the front side of the paper, printing a plurality of print pages having a second imposition on the rear side of the paper with the page in position turned 180°, checking that the first and second impositions of the front and rear sides coincide, correcting the first and second impositions using the control unit when the checking step determines the first and second impositions do not coincide, and preparing a print original with the first and second impositions coinciding.