Organza is a fabric that's light and slightly sheer, with a bit of a shine to it. Formal gowns and wedding dresses are sometimes made using organza.
Organza gets its name from the Italian name for a strong silk thread, organzino. This fancy textile is traditionally woven from silk, with newer, less expensive versions made of polyester. Organza is distinctive for being light and sheer — but also stiff, holding its shape rather than softly draping. A lavish gala would be the perfect occasion to wear an elegant organza gown.