Chiffon

Chiffon from the French word for a cloth or rag is a lightweight, balanced plain-woven sheer fabric woven of alternate S- and Z-twist crepe (high-twist) yarns. The twist in the crepe yarns puckers the fabric slightly in both directions after weaving, giving it some stretch and a slightly rough feel.
Chiffon is made from cotton, silk, or synthetic fibers. Under a magnifying glass it resembles a fine net or mesh which gives chiffon some see-through properties. Chiffon made from natural fibers can be dyed to almost any shade, but chiffon made from polyester requires specialized disperse dyes. 
When sewing chiffon, many crafters layer tissue paper in between the two pieces being sewn together. The tissue paper helps keep the fabric together, with the rough surface of the tissue holding the chiffon in place while it is handled. After sewing, the tissue paper can be carefully ripped out. Chiffon is also pinnable, as it will spring back, concealing pin marks. As a general rule, sewers are advised to work slowly and steadily with this fabric, taking care not to run it through a sewing machine too quickly lest it bunch and gather.