Bitumen is used for aging techniques. It can be applied to wood, ceramics, metal, plaster, and leather. When bitumen is used on wood, a rustic, aged look is achieved. One advantage is that this substance protects and prolongs the lifespan of your pieces. It is water-soluble. It can be applied with a brush diluted with water. Composition: Water, Additives, and Asphalt Resin.