I have been constructing a rock background with construction foam covered with Fastset Repair Mortar Mix and Acrylic Fortifier. How many layers of the mix should I apply to the background. I have 2 on it now and it looks very good. The coverage seems very good.

Also I would like to give the mortar mix some color to simulate rock better. Any recommendations on what type of acrylic paint to use? I have tons of acrylic craft paint at my disposal. The type of paints you can get at Hobby Lobby or Michael's. I will be applying a thing wash of the paints to bring out the highlights.

Mike