sb wrote:
Not sure about the coating, but I have used Nation's Photo Lab to make enlargements mounted on half-inch "Gatorboard" which is very stiff, won't warp, and yet is not very heavy. I then glue two 1x2" boards to the back and attach a wise between those for hanging. This projects the photos out from the wall and really makes them stand out nicely.
WOW....almost the same technique I use. The two strips on the back lets the picture lay flat. I use a special clip that presses into the GB. When cutting the GB be sure your lines are straight and your knife is sharp. I precut to 5x7 and 8x10 as most of my pictures are printed in that size and buy the GB that has self adhesive backing. GB comes in black or white up here in Canada.