Rayon is a semi-synthetic fiber, made from natural sources of regenerated cellulose, such as wood and related agricultural products. It has the same molecular structure as cellulose. It is also called viscose. Many types and grades of viscose fibers and films exist. Some imitate the feel and texture of natural fibers such as silk, wool, cotton, and linen. The types that resemble silk are often called artificial silk.

The fibre is used to make textiles for clothing and other purposes. Rayon production involves solubilizing cellulose to allow turning the fibers into required form. Three common ways to solubilize are the cuprammonium process, not in use today, using ammoniacal solutions of copper salts; the viscose process, the most common today, using alkali and carbon disulfide; and the Lyocell process, using amine oxide. The last avoids the neurotoxic carbon disulfide of the viscose process but is also more expensive.