Miniature models are commonly made of metal, plastic, or paper. They are used to augment the visual aspects of a game and track position, facing, and line of sight of characters. Miniatures are typically painted and can be artfully sculpted, making them collectible in their own right. Pre-painted plastic figures, such as Clix miniatures produced by WizKids and unpainted plastic figures for Warhammer by Games Workshop, have become popular. The hobby of painting, collecting, and playing with miniatures originated with toy soldiers, though the latter were generally sold pre-painted.