Tadelakt is a technique of applying polished stucco. It involves the application on walls of very fine lime plaster and quartz sand which are then polished with stones. This particular polishing endows the material with a peculiar brilliance. The surface becomes plastic and very pleasant to the touch, it is waterproof and acts as a fungicide, and therefore it is particularly adapted to bathrooms or other areas affected by problems of humidity. In the ancient world, this technique was much appreciated by Roman architects, who used it as to substitute for marble in the higher parts of buildings. Today it is still very widely used in the countries of the Maghreb and is highly valued by many contemporary architects for its particular decorative qualities.