Each horse is cast in a two to three piece model. Both halves are then put together and the seams are sanded and polished. Markings and color patterns are usually obtained by using a stencil known as a mask, although most older models were airbrushed by hand, with markings such as undefined socks or a bald face merely left unpainted. Most detailing, such as eye-whites (common on 1950s and 1960s models and is now enjoying a resurgence in modern models), brands, or other individual markings are painstakingly hand-painted. Sometimes, a variation in the paint job occurs. A variation is a difference, usually in the paint job, of one or a minority of a model as they came from the factory. The reason for variations is rarely known. For example, there is a common model typically called the Proud A