How to Paint Styrofoam | eHow.com
Styrofoam is notoriously difficult to paint if the wrong type of paint is used or the foam isn't coated with a primer first. Some types of paints and spray-paints may chip quickly off after drying or damage the foam.
How to Paint Styrofoam to Look Like Aged Stone | Hunker
When it comes to fake substitutes for real stone, Styrofoam is a classic material choice used widely in stage and cinema productions. Though significantly softer and lighter than stone, and essentially not durable at all, Styrofoam closely resembles stone's textures when properly painted.