Abstract: A printing press includes a pair of in-line central impression cylinders which rotate about parallel axes. A web which is printed on the central impression cylinders is advanced from one of the cylinders to the other along a path which is perpendicular to the axes. The web is advanced from an unwind to the first central impression cylinder along a path which is parallel to the axes, and the web is advanced from the second central impression cylinder to a rewind along a path which is parallel to the axis. The web path between the central impression cylinders is relatively short, and the printed side of the web does not contact any rolls except possibly a laydown roll before the second impression cylinder. The central impression cylinders and the plate rolls are driven by different servo motors, and a controller controls the servo motors for adjusting the repeat of the printed images.

Abstract: A preprinted web having a plurality of first repeating images is reprinted with a plurality of second repeating images which are in register with the first images. A register mark is printed on the web for each of the first images. When the web is reprinted, the positions of the register marks are sensed and compared with the positions of the second images, and the unwind tension of the web is adjusted to maintain the relative positions substantially constant.