Abstract: A paint spray rig is disclosed for applying "high gain" reflective paints to a motion picture projection screen. The rig includes a tower which extends vertically of the screen and which can be indexed laterally across the screen. A paint spray head is carried by a carriage assembly that is vertically movable on a tower. The spray head can be moved towards and away from the screen under the control of ultrasonic sensors that measure the distance between the spray head and the screen, for maintaining the distance substantially constant. The spray head can also be moved progressively in the vertical direction with respect to the carriage so that it is at the bottom of the carriage for painting the bottom edge of the screen and at the top of the carriage for painting the top edge of the screen. The spray head can also be swapped from one side of the carriage to the other for painting opposite side edge portions of the screen.