Stone tile is a thin modular stone unit, commonly 12 in. square (30.5 cm) and 3/8 in. (10 mm) thick. Other popular sizes are 15 in. square (38 cm), 18 in. square (46 cm), and 24 in. square (61 cm); these will usually be thicker than the 12 in. square. The majority of stone tile has a polished finish, but other finishes such as honed are becoming more common. Almost all stone tile is mass-produced by automated stone tile lines to identical size, finish, and close tolerances. Exceptions include slate flooring tile and special orders: stone tile with odd sizes or shapes, unusual finishes, or inlay work. In summary, the automated stone tile line is a complicated complex of cutting and calibrating machines, honing-polishing machines, edging machines that put on flat or rounded edges, and interconnecting conveyors to move the stone from the slab input to the final stone tile product. The stone for stone tiles is most commonly marble, but often is granite, and sometimes limestone, slate, or quartz-based stone. Common colors are white and light earth colors. Much of the stone for this application is produced in Italy and China.