Cut out a nice slab of the insulation board. I made mine about 2' x 1.5'
Either draw a epitaph on a piece of 8”x11” paper or print out a epitaph. Pin it to the board.
Next, take an Exacto Knife and trace around the edges of the lettering. It is very important to score the insulation.
Next, Use a Dremmel to remove the material from the lettering.
Next, take the board, and cover it with Gray Paint as thick as you can. While the paint is still fresh, cover it with sand.
Let it dry and the end result looks like stone.