Devices and methods to enable a sheet conveyance system within a printing device. According to an apparatus herein, a sheet supply device feeds substrates to a printing system. The apparatus includes an impression cylinder. A first gripper is positioned in a first location on a circumferential wall of the impression cylinder. A second gripper is positioned in a second location on the circumferential wall of the impression cylinder. The second location is angularly spaced apart from the first location around the circumferential wall. A cover selectively covers the second gripper. Responsive to the first gripper gripping an edge of a substrate of a first length supplied from the sheet supply device, the first length being greater than the length of the circumferential arc between the first gripper and the second gripper, the cover provides a smooth curved surface over the second gripper.