Abstract: A method and apparatus for is provided for supporting and connecting drier cassettes of an air knife type of drier. The drier cassettes exhaust air on traveling printed matter and are joined and supported by expander units that also exhaust air on the printed matter to increase drying efficiency. Gas or air is supplied to either the drier cassettes or the expander units or both and window apertures may be provided to allow the gas to communicate between the drier cassettes and the expander units. The relative exhaust pressures of the expander units and the drier cassettes may be regulated to create a pressure gradient on the printed matter as it travels through the exhaust so that the path of the paper suffers from less disruption.