The printer switchable between simplex and duplex mode of operation on a page by page basis makes use of a single simplex print engine. Duplex printing is accomplished by the reinsertion of a simplex printed page into the input of the print engine in a flipped mode so the other side of the printed page can be printed by the print engine. This printer also includes apparatus that dynamically switches the operation of the printer from duplex to simplex mode of operation when the printing commands input from the associated processor indicates that the other side of a simplex printed page is a blank page. This enables the print engine to eject the simplex printed page directly to the output paper bin without having to cycle this simplex printed page back through the print engine even though there are no characters to be printed thereon. This blank page suppression or simplex/duplex mode switching thereby increases the throughput of this printer system by avoiding the unnecessary delays occasioned by cycling a page of paper through the print engine when nothing is to printed thereon.