That'll give you a 3/16-in. reveal. Place the top piece and hold the trim 3/16 in. away from the jamb at both ends and along the base of the window casing. Nail the trim to the jamb with 1-in.

Trim and molding aren’t just the icing on the cake ... we hid our existing radiator piping and added new electrical wiring behind them Door and Window Casing Like other types of molding, casings were ...