individual, or retained for use by the commissioner. Some thangka have inscriptions on their back recording that they were the personal meditation image (thugs dam) of a notable monk. Most artists were probably monks, although lay artists seem to have also existed, as they did for metalwork sculpture. The commissioner would provide the materials, which were often valuable, and by tradition the compensation to the artist was regarded as a "gift" rather than a fee. The word "thangka" means "thing that one unrolls" in Classical Tibetan. Thangka are very rarely signed, but some artists are known, more because they were important monastic leaders than famous as artists. Painting was a valued accomplishment in a monk. The earliest surviving Tibetan paintings on cloth are from the Mogao Caves at Dunhuang on the Silk Road in Gansu province, China. The "Library Cave" there was a repository of old or worn out manuscripts, paintings, prints, textiles and other items which was sealed off in the 11th century, after several centuries of deposits. Many of the paintings have Tibetan inscriptions or are in a style that can be recognized as Tibetan, as opposed to the dominant Han Chinese style and some pieces reflecting Indian styles. Though they are hard to date, it is thought that these pieces mainly come from a period c. 781–848 during Tang dynasty rule. Surviving tangkas on cloth certainly from Tibet itself start in the 11th century, after the revival of Buddhism; there are some 20 surviving from the 11th and t12th century. Such early examples typically have compositions that are already complex, but less so than in later examples. Later the typical compositions show a central figure flanked by smaller figures, often in framed compartments, or surrounded by flaming halos or seated on small clouds. Behind these figures a landscape background including much sky is often indicated, though little of it may be visible. The central figure may be a deity, arhat, or important monk, and the same groups make up the background figures. Several of the figures may be different "aspects" or reincarnations of each other according to Buddhist theology. In the example at left the flanking bodhisattvas are in a style, one of several found in such figures in this period, that appears derived from central Indian art. Over the following centuries Tibetan painting, both on walls and thangka, continued to develop in its distinctive style, balancing