The basement windows now have jambs! I made them out of pine nailers salvaged from the roof of an old house which was being remodeled; they closely match the color and nail-riddled texture of the ceiling. The best part is that they cover up much of the hideous white vinyl surround of the new windows. I still have a little insulating and caulking to do, but not much. They will remain just like this – they project roughly 3/8″ from the face of the wall. I thought a frame would look too finished and come too close to the ceiling joists for visual comfort. I’m happy with the clean simplicity of the jambs by themselves.