While I could have wrapped the aluminum backdrop directly around the end of the wall, I decided to use a larger radius (10 inches) to make the turn easier on the eye. This required the backdrop to angle away from the wall to meet the larger radius, which in turn required the trim channel to be mounted on the same angle.

This image shows one side of this supporting structure. The trim channel creates it's own curve from the wall proper to the angled support. The backdrop that wraps around will be suspended from the end of this channel and will be self supporting around the bend.