This 4″ symmetrical casing offers an farmhouse or heritage design. Usually corner blocks and plinth blocks are used with this style of casing. Casing is used to trim around doors and windows. It covers the gap between the drywall and the jamb. Casing is often the most prominent trim feature in your home and should be thicker than the baseboard. To increase the width and depth of the casing you can add a back band.