Chair Rail
Chair rail or chair railing is a molding applied about 36" (or 1/3 of the wall) up from the floor, which encircles the room. Originally it was used to prevent chairs from damaging walls, but today it is used primarily as a key decorative piece to set the tone of a particular room - especially in traditional and colonial design.
Chair rail molding, in rooms with higher ceilings, can often times be used in conjuction with other moldings for a "compound" molding.
Installation Tip
When a chair rail intersects a window or door casing, consider a simple mitered return on the chair rail.