The theory behind black art is that everything in black won't be seen against a black background. This means at the start of the performance, there can be many items on the stage covered in a black cloth and they won't be seen. The magician simply removes the cloth and voila, an item has appeared. Disembodied bodies can move around by wearing black trousers, or a black jumper. Assistants dressed completely in black can make objects, including people, fly around the stage.