Use Rit® DyeMoreTM on 100% polyester, polyester / cotton blends, acrylic, acetate, nylon and even some plastics. One bottle will dye one pound of dry polyester fabric. If dyeing acetate, acrylic or nylon, one bottle will dye two pounds of dry fabric. Important: due to the complexity of dyeing synthetic fabrics, you must use this dye in a stainless steel pot on your stove top to maintain a high water temperature throughout the duration of dyeing. Cannot be used in a washing machine.