In theater, a brace is a sliding piece of wood or metal with a 'butterfly' winged nut to make it longer or shorter to fit the flat used to stabilize a flat set piece such as a flat. The nut is used, so that it can be changed more quickly than a screw to the floor during a quick change. Usually, a brace is painted black to make it less noticeable to the audience. Braces are often used to form a triangle between two perpendicular items (like a vertical flat and a stage. They can also make a flat piece stronger by forming an X-shape between all four corners. Another way to brace a rectangular flat is to use special braces, called toggles which run at regular intervals, parallel to the short end of the flat, effectively breaking it into many smaller, stronger rectangles.