Trim out your space with Diamond Plate Aluminum Crown Molding featuring heavy duty all aluminum construction. Available in 4 ft and 8 ft lengths as well as custom sizes. Pre-formed inside and outside corners eliminate miter cuts making installation even easier. The use of crown molding has been a long standing architectural technique to smoothen the transition from the wall to the ceiling. Crown Molding is a nail-up installation like traditional crown molding. Simply hammer in the nails at slight angles to "lock" the Crown Molding into place.