Calder cut shapes from sheet metal, painted them matte, and hung them from bare wire so the air would do the rest. Duchamp called them mobiles in 1932. Nothing is centred: every weight hangs at an unequal distance from one pivot, and the whole thing still rests.

So this system treats the white wall as structure, not emptiness. Shapes are flat fills with a cut edge. Rules are hairline wire. Shadows are hard-edged plates sitting at a distance from the object that casts them, because that travelling shadow on plaster was always part of the work.