From the French word meaning cloth, "chiffon" does not refer to a specific material, but rather the method in which it is made. Chiffon may be made out of a natural material like silk or a man-made material like polyester. These fibers are then woven together to create the sheer, porus fabric known as chiffon. Whether or not to iron the chiffon depends on what type of chiffon it is.
Start with a piece of slightly damp polyester chiffon. Lay it flat on the ironing board.
Set the iron to a low or cool setting.
Lay a towel over the chiffon.
Press down onto the towel and continuously move the iron over the towel until the wrinkles have disappeared from the fabric.
Repeat on the other side of the chiffon, if it has two sides like a blouse.