In art, the term 'undercut' means to cut away the bottom/underside of a material so as to create an overhanging or a concave portion in the form or relief. . It is a carving to create a projection or overhang by cutting the material. The term is also used to refer to an awkward angle in the form or surface of a three dimensional object that may prevent removing the cast from its mold without extra effort. Care should be taken to design mould in such a way so as to eliminate this problem. Waste molds or piece molds may be used to cast objects with overhangs. The term is also seen used in relation to relief sculpture and sculpture in round. It is a cut behind a form so as to release it from the background. Sculptors use this technique to make surfaces and lines in a sculpture/form appear as if they continue round the back part of the form. It is also used to give a chiaroscuro effect to forms. An undercut traps shadows in between a form and the background. In some sculptures this creates a chiaroscuro effect.