Silk is a natural protein fiber. It is similar to wool in that it is composed of amino acids arranged in a polypeptide chain, but it has no crosslinks. It is produced by the cocoon of a moth. Silk is universally accepted as a luxury fiber and has a combination of properties not possessed by any other fiber. It has a dry tactile hand, unique natural luster, good moisture absorption, lively suppleness and draping qualities and high strength. The beauty and hand of silk and its high cost are probably responsible for the development of the manufactured fiber industry. In fact it is the physical nature of silk that some manufactured fibers attempt to duplicate.

Uses –Because of its unique properties and high cost, silk is used primarily in apparel and furnishing items. Silk is extremely versatile and can be used to create a variety of fabrics from sheer, gossamer chiffons to heavy, beautiful brocades and velvets.

Because of silk’s absorbency it is appropriate for warm weather wear and active sportswear. Because of its low heat conductivity it is also appropriate for cold-weather wear. In fact, silk's absorbency makes it comfortable to wear in warm weather and while active, while its low conductivity keeps warm air close to the skin during cold weather. It is often used for clothing such as shirts, ties, blouses, formal dresses, high fashion clothes, lingerie, pyjamas, robes, dress suits, sun dresses and kimonos. Silk underwear, socks, and leggings are popular due to silk’s soft hand, good absorbency and wicking characteristics. Silk is available in a range of apparel from one-of-a-kind designer garments to low priced discount store T-shirts.

Silk's attractive luster and drape makes it suitable for many furnishing applications. Silk is frequently used in upholstery, wall covering fabrics, and wall hangings. Occasionally, beautiful and expensive handmade rugs are made of silk. Liners for sleeping bags, blankets and bedsheets of silk feel warm, soft, and luxurious next to the skin.

While on the decline now, due to artificial fibers, silk has had many industrial and commercial uses; parachutes, bicycle tires, comforter filling and artillery gunpowder bags.

A special manufacturing process removes the outer irritant sericin coating of the silk, which makes it suitable as non-absorbable surgical sutures. This process has also recently led to the introduction of specialist silk underclothing for children and adults with eczema where it can significantly reduce itch.