Pottery and ceramics in Iran dates back to 12,000 years BC. Most important production centers for pottery are in the provinces of Laleh Jin about 25 km of hamedan and Farasfaj at Toyser Kahn. Pottery is usually done with red clay by hand, molding and wheeling, but other clays like black clay and white clay are also used. Different kinds of decoration such as engraving, embossing, lattice working ornamented decorations are applied to Iranian clay artifacts. Painting on clay is done in two ways, under gazing and over glazing. In Esfahan most of flower-and-bird and specially fish designs are worked as under glazing with the name of seven-color painting. Turquoise blue pottery of Shahreza is another example of under glazing painting which is famous in the world; in this work of art black linear designs are shown under a layer of turquoise glaze. Forming white clay by a wheel is of the distinguished products of Esfahan that due to the hardship of its making it is produced in limited number.