The production of a thangka is an act of devotion and the process is carefully formalized. Linen (or now more commonly cotton)is stretched and lime called gesso. Iconography is bound by strict mathematical measurements. A grid is drawn onto the thangka before outlines are sketched in charcoal, starting with the main central deity and moving outwards.

Colors are added one at a time, starting with the background and ending with shading. Pigments were traditionally natural: blue from lapis, with at least a little gold. The last part of the thangka to be painted is the eyes, which are filled in during a special 'opening the eye' celebration. Finally a brocad backing of three colors and a 'curtain' are added, the latter to protect the thangka.