Stage: Curtains and flat backdrops can be placed horizontally across any part of the stage. Backdrops and curtains include any aspect of the set which hangs from the ceiling to the floor. This might be flat elements of the set which are used to frame the actors, such as false building exteriors. Curtains are like lights, in that they have a special token which indicates orientation, and can be “filled up” like a vessel. A set designer can cut out, or mock up a flat curtain stage element, and place it in the ‘back drop editor’, and assign the backdrop to that token. When there is no backdrop in the backdrop editor area, it shows how the current time index appears to audience members.