Abstract: A buffer device temporarily retains a number of sheets between a printing apparatus and a finisher, such as a stacker-stapler. The device defines a baffle for the passage of sheets therethrough. Arranged in series in the baffle is a set of gates. Each gate is positionable in an open position or a clamping position that causes a sheet passing nearby to be stopped. By clamping each of a set of sheets as it passes through the baffle, and then setting all the gates to the open position, an accumulated set of sheets can be conveyed out of the baffle substantially simultaneously.