Crown molding is a very popular trim material that's typically installed along the top 2 to 12 inches (5.1 to 30.5 centimeters) of a wall [source: Kalyn]. It's used to provide a visual transition between walls and ceilings, while helping set the style and décor of the room. Crown molding can also conceal drywall or plaster flaws at hard-to-finish corners and joints, and it may also hide wiring used for lighting and speakers [source: Lowe's Home Improvement]. The size and style of this trim should be chosen carefully to fit the dimensions and design of a room, as overly large molding can shorten the look of walls.
Many crown molding profiles are styled after ancient column designs. Ogee molding has a simple S-shape, while rosevine profiles feature elegant flowers and vines. Egg-and-dart molding is composed of a series of ovals and lines, while dentil molding is characterized by patterns of squares or rectangles. Crown molding with a cove profile has a simple, curved shape that's appropriate for modern décor [source: This Old House].