Jim, Hoopers gallery in London use this method of mounting prints for some artists. When done correctly it looks excellent but is very expensive. The prints are mounted right to the edge of the aluminum and hung using two pieces of wood, one fixed to the back of the mount and the other fixed to the wall. The wood is cut at 45 degree angle and just slot into each other keeping the image level and fixed to the wall. From the front there is no sign of how the print hangs it looks suspended. I also have one 8" x 8" print at home mounted in the centre of a 12" square piece of aluminum it looks very good but the aluminum is easily marked.