You may be used to it under a different name: Rayon. Most european labels will have it as Viscose, with the American equivalent of rayon. It can be prepared in such ways to mimic the feel of cotton, wool, silk or linen, though most of the time they seem, especially in womens clothes, to try to hit closer to silk than cotton Read this article: http://viscose.webs.com/ , it contains detailed information about it
Viscose in its most commercial form is rayon. It has a silky feel, and is used extensively for clothing manufacture. Though it breathes like cotton and has a good drape, it can wrinkle easily and shrink in hot water.
Viscose is created from a combination of natural and man-made components, and it can be made into the more common form of rayon used for many types of textile products, including clothing. Viscose has a silky appearance and feel, and has the ability to breathe in a manner similar to cotton.