A marble is a small toy often made from glass, clay, steel, plastic, or agate. They have different sizes. Most often, they are about 13 mm (1⁄2 in) in diameter, but they may be less than 1 mm (1⁄30 in) to over 8 cm (3 in), while some glass marbles for art are over 30 cm (12 in) wide. Marbles can be used for games called marbles. They are often collected, both for fun and for their colors. In the North of England, the toys and the game are called "taws", with larger taws being called bottle washers after the use of a marble in Codd-neck bottles, which were often found for play. These toys can be used to make marble runs, a form of art, or they can be used in marble races, a kind of race using marbles.