I have some molding that I mad in a Williams and hussy molder. I am painting the trim with airless sprayer. I tried to get the edges the best I could when I sprayed the faces. I still needed to spray the edges better. The thin edge was easy to spray because the wide edge was wide enough to stand the trim up on. To do the wide edge the narrow edge would not support the trim standing up. I had this small piece of shelving left over from a closet. This worked well to support the trim as I sprayed it.