Once the beam pendants were installed, and the top of the beam covered, we installed WM 54 crown, its a small 2 1/4 x 9/16 crown, down both sides of the beam. We chose WM 54 because it has a 1 7/8 inch 'rise' when it is installed. That along with the 1/4 MDF cover lines up just right to enclose the space from the ceiling to the top of the beam and cover.