All thangka imagery shares in this mandalic quality and function. Thangkas are used in processions, and monks carry their personal thangkas with them when visiting other monasteries. Their purpose is not to decorate otherwise empty walls but to serve as aids to ritual worship and meditative visualization, which is at the heart of Tibetan Buddhist spirituality. The finished painting is usually but not always placed in a frame of brocade, which further emphasizes the sacred nature of a thangka. All the significant elements of a thangka are designed according to exacting standards laid down in the text books.
Special care is taken with the idealized proportions of deities and gurus.
Buddha figures follow the prescribed dimensions for the Buddha himself, whereas female deities follow the standard for Tara and wrathful deities fit into the design grid for Vajrapani. Even the colors for each type of figure are prescribed, leaving little room for improvisation. The main deity is always painted in the center, with lesser deities and sacred entities surrounding it in hierarchical fashion. Thus the gurus are painted directly above the head of the central figure, with Buddhas and Bodhisattvas in what would be the sky and lesser deities in the lower half of the picture. Sometimes in a bottom corner, a humble practitioner is depicted in an attitude of supplication.