A variety of tussar silk cultivated in various regions of Chhattisgarh — including Raigarh, Bilaspur and Janjgir-Champa — Champa silk occurs in shades of brown, cream and dull gold. Bhagalpur in Bihar is a major producer of tussar and other indigenous varieties of silk and is home to over thirty thousand dyers, spinners and weavers.

Silk weaving in India has a history that goes back to the Vedic period (1750–500 BCE), with tussar silk being used in eastern and northeastern parts of India since the ninth century CE. The wild silk extracted from the tussar worm (Antheraea mylitta) is coarser and warmer than mulberry silk, extracted from Bombyx mori, a variety of domesticated silkworms. The tussar cocoon from which the threads are extracted is known as kosa fal in the Chhattisgarhi language, and the woven fabric is known as kosa silk.

The kosa silk of Champa is internationally recognised for its high quality and is characterised by its uneven textures and bright colours. The silkworms that produce the silk are reared on the bark of the Arjun (Terminalia arjuna) and Saj (Terminalia tomentosa) trees. They spin cocoons while hibernating, from which long filaments of silk are extracted. These filaments are then treated and reeled out as continuous threads. The resulting silk is woven on jacquard or pit looms, which are used to produce textiles such as sarees, dhotis, stoles, kurtas, yardage and home furnishing for the domestic and international market.

There are three types of Champa silk sarees: the phera saree, featuring a plain body with a kumbha (temple) motif along its borders; the jala saree, woven using the meticulous jala technique, which allows the weaver to create various floral and foliate motifs and geometric patterns; and the khapa or patiya saree, wherein supplementary weft threads are used on the pallu to create a ribbed design with continuous line and dash patterns. The sarees are characteristically woven using extra weft threads to add ornamentation to the garment.

Traditionally, flowers such as palas (for yellow), rora (for red) and a combination of lac and Hirasaki (for black) have been used to dye kosa silk. More recently, acidic dyes have become popular for their bright colours.

In 2011, Champa silk sarees and fabrics from Chattisgarh received Geographical Indication (GI) status from the Government of India for their territory-specific production and characteristics.