I am making a 28 inch wide x 20 inch high leaded glass window. It will be exposed on the inside but will have a thermopane panel on the outside to protect it from the elements. It will have a 1/2 inch zinc channel around the perimeter and will be mounted in a fixed wood window sash. Do I need edge to edge reinforcing? If I do, since there are no straight lines all the way through the design, what do you recommend I use?