Panel mould is a decorative trim applied to the wall to add a visual relief to the wall. The panel mould is sometimes accompanied by a chair rail. Panel moulding can be used on the full face of the walls, or partially up the wall. On applied panel moulding, the 4 pieces are mitred together to form rectangles and are applied to the surface of the wall. In sunken panel applications it will have a rabetted edge to accommodate the style and rails of the panels. The style and rails are the vertical and horizontal pieces that for the wall paneling. In sunken panel designs, the panel mould is often referred to as a bolection mould.