Thangka, pronounced "thanka," is simply defined as a "picture painting." In Tibetan Buddhism, a thangka is a scroll painting framed in silk, which fulfills various religious functions. The themes of iconography are fixed by tradition and are based on three principles: expression, proportion, and detail. Commissioning the painting of a thangka and the painting itself are considered highly meritorious actions.
The images are painted on linen with vegetable- and mineral-based pigments. In some cases they serve as visual reminders of general Buddhist teachings—examples are the wheel of life or the depictions of the previous existences of the Buddha. In other cases thangkas play an important ritual role—as, for example, detailed paintings of central personalities of a particular school being used for taking refuge. However, the most important role of the thangka is connected with the performance of sadhanas, where the picture functions as support for memory in the process of visualization. Painted mandalas fulfill the same purpose.
Adapted from The Shambhala Dictionary of Buddhism and Zen, by Michael S. Diener, Franz-Karl Erhard, Ingrid Fischer-Schreiber. Translated by Michael H. Kohn. Permission from Shambhala Publications.