Polyester viscose is a blend of viscose, which is a form of rayon, with polyester, which increases the viscose's wet strength, giving it the durability to handle washing and drying by machine. The blend makes the fabric stronger, but it retains the same drape and feel of standard viscose rayon.
Viscose rayon is similar to other natural fibers, such as linen or cotton, even though it is man-made. Viscose is made from a cellulose xanthate solution made from wood pulp. The process for creating it was discovered in the early 1890s and was first manufactured in the United States for commercial use in 1910.