[caption id="attachment_1499" align="aligncenter" width="167"] Spandex Fibre[/caption]
Lycra, Spandex and Elastane are all names for the same fiber. First developed by DuPont, Lycra is a polyurethane fiber. The two prepolymers, one long and flexible and the other short and stiff, link to form a folded or twisted fiber which can be stretched up to five times its length. When tension is released, the fiber springs back to its original length.
Diagrams of Spandex...
A sample of rayon from a skirt, photographed with a macro lens. from Wikipedia
The oldest man-made fiber is rayon. It is formed of dissolved cellulose extracted from wood. Although almost any woody plant can supply the wood, some of the more common sources were conifers such as spruce, hemlock and pine. That was when most rayon was produced in North America and Europe. Now that the largest producer of rayon is in India, woods from that part of the world are commonly used,...