Within the group of oriental carpets, the Anatolian rug is distinguished by particular characteristics of its dyes and colours, motifs, textures and techniques. Examples range in size from small pillows ("") to large, room-sized carpets. The earliest surviving examples of Anatolian rugs known today date from the thirteenth century. Distinct types of rugs have been woven ever since in court manufactures and provincial workshops, village homes, tribal settlements, or in the nomad's tent. Rugs were simultaneously produced at all different levels of society, mainly using sheep wool, cotton and natural dyes. Anatolian rugs are most often tied with symmetrical knots, which were so widely used in the area that Western rug dealers in the early 20th century adopted the term "Turkish" or "Ghiordes" knot for the technique. From the 1870s onwards, the Ottoman court manufactures also produced silk-piled rugs, sometimes with inwoven threads of gold or silver, but the traditional material of the majority of Anatolian rugs was hand-spun, naturally-dyed wool.