The thangka is a painting on cloth, mounted in silk and made so that it can be rolled up and moved, and that portability is bound up with the mobile and teaching life of Tibetan Buddhism.
Painting as support for practice
A thangka depicts a buddha, a deity, a teacher, a mandala or a scene, painted to exact iconographic rule since the image is a support for meditation and devotion rather than a free work of art, and every proportion and attribute is fixed by tradition so that the figure is correctly present. The finished painting is mounted in a brocade frame with a cloth veil that hangs over the face when the work is not in use, protecting it and marking that it is uncovered for a purpose. The making of a thangka is itself a meritorious and disciplined act.
Rolled, carried, unfurled
Because it is painted on cloth and mounted to roll, the thangka can be stored, transported and unrolled where it is needed, which suited a religious world of travelling teachers, tents and monasteries, and it could be displayed for a teaching or a festival and then rolled away. The greatest examples are the huge applique thangkas unfurled down a hillside or a monastery wall on particular festival days, shown to great crowds for a few hours and then put away for the year. The object is therefore not a fixed altarpiece but a portable and revealable image, made to serve practice wherever it is carried.