Abstract: A web coating apparatus having a partially submerged drum in a tray of coating material. The drum rotates and transfers coating material from the tray to a web material passing over the drum. A control system carefully controls the level of the coating material in the tray using an ultrasonic fluid level sensor in combination with a programmable system that can add or remove coating material to or from the tray.

Abstract: A printing supply system for a plurality of coating substances. The system includes a first supply line for supplying a first fluid and a second supply line for supplying a second fluid. A first valve member is connected to the first supply line and to the second supply line for guiding flow therethrough. A supply tube is connected to the first valve member for providing a selected fluid to a press, the selected fluid being one of either the first fluid or the second fluid. A drain tube is provided for extracting the selected fluid from the press. A second valve member is connected to the drain tube for guiding flow therethrough. A first return line and a second return line are connected to the second valve member. A conduit is positioned between the supply tube and the drain tube for enabling draining of the supply tube and the drain tube between selection of the first fluid and the second fluid.