This is the back of the cornice , this is the bracing for the wall installation , I screwed a 2x4 that fit the width of the cornice to the wall studs with 4 large screws . From the sides I screwed in another 4 screws two on either side , that is a total of 8 screws securing this piece to the studs.
I attaached two triangle shaped pieces of wood to the frame to allow the piece to hang on the stud , somewhat , which makes installing it easier .