Organdie finishing is a process that converts opaque fabrics into translucent fabrics, usually applied to cotton or polyester materials. The fabric is dipped in sulfuric acid which partially dissolves the fiber surface, leaving a stiffened cellulosic film. This makes the fabric permanently crisp and transparent. Lightweight woven fabrics like voile or muslin work well for this finish. The acid exposure time controls the resulting stiffness. After finishing, the organdie may be bleached, dyed, or embroidered. It produces a popular sheer fabric used traditionally for women's dresses, men's collars, curtains, and often as a lining for structure.