Some areas are left unshaded, to give the effect of large or protruding features. The most complicated is painting flames in detail, each tongue of fire given its own colorful and seamless blending of red, yellow and orange. Ponds and lakes are usually drawn in a triangular shape, during a secondary sketch of horizontal lines of the same width. This allows for the borders to be shaded later on. The bodies of water are filled in with mineral colors of medium blue and finished with white outlining.
Most depicted objects require outlining, especially in small and thin details.
Indigo and lac dyes are used for outlining shaded areas of the same color, and in areas with white or gold. Lac dye is used for the last outline to be drawn. All accomplished thangka painters have perfected excellent outlining techniques. It shows accuracy and the painting must have smooth gradations to impart a look of depth or volume where it is needed. Some artists place the stretcher on their laps or in front of their crossed legs, as they work.