Abstract: A printing apparatus for printing on a substrate is provided. The apparatus includes a substrate feeding system for feeding the substrate through a printing station in the apparatus and a printing system at the printing station for printing on the substrate. The substrate feeding system includes a drive roll upstream of the printing station; a drive motor for driving the drive roll, a tension roll downstream of the printing station; a tension motor for driving the tension roll, a coupling assembly coupling the tension motor to the tension roll and effective to apply a pivotal force to the tension motor in one direction about the axis of the tension roll according to the actual tension on the substrate, and a biasing-force device effective to apply a pivotal biasing force to the tension motor in the opposite direction about the axis of the tension roll according to the desired tension on the substrate.