This is our range of round birch plywood frames which are suitable for outdoor use as long as it they properly sealed with a few coats of yacht varnish (on the back and sides but not where the mosaic tiles are to go), - 5 ideally ! To prolong their life you should revarnish every couple of years. The edge on our framed boards protrudes 5mm above the surface of the board which is ideal for our glass and ceramic tiles which are 4mm thick.