A method of processing sheets of different formats, including feeding the sheets of different formats in a feeding direction one behind the other, and at a certain feeding speed, to at least two collecting drums, the at least two collecting drums each having cylindrical lateral surfaces, driving each of the at least two collecting drums about a respective axis of rotation at a circumferential speed, the circumferential speed corresponding to the feeding speed of the sheets, temporarily securing at least some of the sheets on one of the at least two collecting drums to form a sheet stack, detaching the sheet stack from the at least one of the at least two collecting drums, and bringing together the sheets or the sheet stack detached from the at least one of the at least two collecting drums with sheets or a sheet stack detached from another one.