Abstract: A printing system where the alternating current energized semiconductive layer of the impression roller has a covering of dielectric material with a controlled thickness, and with a dielectric constant many times greater than that of the web, such that a major portion of the applied electric potential is transmitted to the web by means of a reactive current through the covering.

Abstract: A register control system is disclosed for maintaining longitudinal or lateral register of a moving web wherein a comparator has a first input controlled in accordance with error count and has a second input controlled by a resistance-capacitance timing circuit with a non-linear characteristic such as to compensate for the non-linear characteristic of the digital to analog converter responsive to error count, and thus to provide a correction motor on time linearly proportional to error count. An adaptive circuit is provided responsive to web speed and providing for a correction cycle with respect to each repeat length of the web at relatively low web speeds, but providing for skipping of alternate error cycles at higher web speed.