March 31, 2014 -- Based on technique and material, thangkas can be grouped by types. Generally, they are divided into two broad categories: those that are painted (Tib.) bris-tan—and those made of silk, either by appliqué or embroidery.
Thangkas are further divided into these more specific categories:
Painted in colors (Tib.) tson-tang—the most common type
Appliqué (Tib.) go-tang
Black Background—meaning gold line on a black background (Tib.) nagtang
Blockprints—paper or cloth outlined renderings, by woodcut/woodblock printing
Embroidery (Tib.) tsem-thang
Gold Background—an auspicious treatment, used judiciously for peaceful, long-life deities and fully enlightened buddhas
Red Background—literally gold line, but referring to gold line on a vermillion (Tib.) mar-tang
Whereas typical thangkas are fairly small, between about 18 and 30 inches tall or wide, there are also giant festival thangkas, usually Appliqué, and designed to be unrolled against a wall in a monastery for particular religious occasions. These are likely to be wider than they are tall, and may be sixty or more feet across and perhaps twenty or more high.
Somewhat related are Tibetan tsakli, which look like miniature thangkas, but are usually used as initiation cards or offerings.
Because Thangkas can be quite expensive, people nowadays use posters of Thangkas as an alternative to the real thangkas for religious purposes.