Tangkas depict a wide range of themes.A considerable number of ancient tangkas have been preserved.However,few Tangkas dating from the Tang and Song dynasties remain. The Sakya Monastery houses a Tangka entitled Sanggyai Dongsha, which contains 35 Buddhist images. Its style is similar to the murals found in the Dunhuang Grottoes. It is said to have been completed during the Tubo Kingdom, and is a rare treasure.The Potala Palace houses three Song Dynasty Tangkas, two of which are kesi (a type of weaving done in fine silks and gold thread by the tapestry method). A portrait of Palma Toinyoi Chuba has a caption written in Tibetan at the bottom of the Tangka saying that it was made at the order of Gyaincain Zhading as a gift for his teacher Chagba Gyaincain. A tangka with a portrait of Kungtang Lama (1123-1194) was made in the late Song Dynasty. Another Tangka, depicting the life of Mila Rigba, describes Mila Rigba's self-cultivation. Experts have concluded that it was made in the Tang Dynasty.
The main theme of Tangka is religion, such as portraits of Buddhas and Bodhisattvas, scenes of saints expounding the sutras, temples, religious personages, and religious stories. Such pictures make up more than 80 percent. Even Tangkas depicting Tibetan history and science have a strong religious flavor.In general, a Tangka depicting a religious theme is divided into three parts:upper, middle and lower, representing heaven, earth and the underworld, respectively. The middle part shows Buddhas,such as Sakyamuni; the upper part shows Bodhisattvas; and the lower part has pictures of monks and guardian deities.
All big monasteries in Tibet house a considerable number of Tangkas. At Potala Palace a two-story building was built as a warehouse for storing Tangkas.On the 30th day of the second month by the Tibetan calendar a prayer ceremony is held. Several thousand lamas from Zhebung Monastery and other temples gather at Potala to hold religious rites and various other ceremonies. Two huge Tangkas with portraits of Buddha are hung on the terrace. This is called "sunning the Buddha."
Today, Tangkas have entered ordinary homes as decorations.In Lhasa there are several workshops specializing in making Tangkas.The prices vary,ranging from 30 to 1,000 yuan each. These can meet the demands of various tastes, and make good gifts for inter-provincial and international cultural exchanges. We can say that Tangkas have become exotic flowers in the garden of traditional Tibetan culture.