Casing defines the overall character of the room and is the most visible part of the trim. It is used to cover the gap between the drywall and the door/window frame. Casing is used generously in spaces and is often the most visible moulding in a room. Casings are generally thicker than baseboard moulding for when the base meets the casing. And like any framing element, the options are endless, from build-ups of multiple pieces to full wraps.
