A third way of shooting a matte allowed the director to shoot the plate normally without worrying about the matte, and add the matte and the painting later.
The film was developed normally, and then the reel was loaded into a rear projector. A sheet of glass in a sturdy frame was placed on a stand in front of the rear projector. A sheet of frosted projection material was positioned on the back of the glass facing the projector. The matte artist then plotted out the area where the painting was to be added. With the filmed and painted images aligned, the painting was executed. The matte artist ran multiple tests photographed from a camera on the opposite side of the projector to ensure a seamless match. With the camera and the rear projector carefully synchronized, the scene was filmed again, this time with the painting blocking out the matted areas of the original footage