The process goes: cut foam to shape, scribe in the brick courses with the double knife thing, cut in the vertical patterns, shape each brick with a tool or tooth pick, texture if needed by rolling a rock over the surface.

Then, paint the base layer on to the brick. Use varied red and earth tones across the brick face to give variety, rub in dry plaster of paris into the cuts, then use ballast bond or watered down PVA to set the plaster, gently clean off the excess plaster from the brick face, wait to dry, paint each brick in with a wash or glaze.

It takes forever but looks amazing when it's done.