The earliest type of Navajo pottery excavated were of utilitarian ware dating from 1500-1700. After the Long Walk in the 1860's, manufactured ware was made readily available by trading posts and this caused a tremendous slowdown in Traditional Navajo pottery making. Pottery was then produced mainly for ceremonial use. Traditional Navajo pottery usually has little or no design. Melted pinon pitch is normally applied, giving it a glossy finish and making the pottery waterproof. Random gray and black markings on the pottery pieces are called fire clouds caused by direct contact with burning fuel during firing. Some pieces are decorated with appliques or designs etched or incised into the pottery. Today's Navajo pottery is not confined to traditional methods and styles, and the craft is experiencing new and creative adaptations such as working with horse hair and clay.