epoxy for background

I wanted to know if anyone has tried using epoxy and sand and or gravel to
cover the inside of the aquarium rear.
My idea is to use epoxy (or maybe silicone) spread on the rear pane and
spinkle with sand and gravel. Hopefully this will add depth and look nice.
In the past I have sprayed the out side with black paint, but there is
still the glare and flat surface. Any info would be a great help.
        Also has anyone used Mylar as a reflective substance?
Larry Jones