Coulage is a surrealist technique, a form of automatic or involuntary sculpture in which a molten material, usually chocolate but also sometimes wax or molten tin, is poured into cold water. The resulting "sculpture" is also called a "coulage," as in "a chocolate coulage". Chocolate coulage in particular tends to form into extremely delicate filaments not conducive to moving, discouraging gallery display, which may be one factor behind the relative obscurity of the method. Coulage apparently also has industrial applications.