Tooth is the surface texture that provides the resistance to brushes and other materials that facilitates productive color application. Too much tooth consumes paint and wears out brushes, too little makes it hard to build colors up to the intensity required. Different mediums require different levels of tooth. Pastels benefit from a granular surface, even mildly abrasive, whereas watercolors are best done on the natural grain of paper. Oil and acrylic painters have a wide variety of preferences for tooth. Those who paint very finely with small brushes will find the weave of very fine canvas adequate, whereas more painterly artists will choose rough canvas and even add chalk or other materials to their ground to make a strong textural ground.