I have 5mm thick sun bleached plywood cut sardines shapes and attached to a reject foam surfboard blank from a local board maker. This board is 550mm wide x 1950mm high and can be mounted horizontally or vertical. I then flame burnt the surface to enhance the greys.
This installation is designed to be used indoor or outdoor (under cover). Hanging is easy onto a heavy duty screw into a wall. Price does not include freight which either you can arrange or we can quote and arrange.