PLEASE NOTE: NOT INTENDED FOR PLASTICS! This purchase is for dyes to be used on Cellulose fibers only. Depending on the application, you will need other auxiliaries to assist in the dyeing process. PRO MX Reactive Dyes (Procion MX) are easy to use, versatile, permanent, and are the most popular dye for tie-dye. They are designed to permanently dye cellulose fibers -- plant based fibers like cotton, linen, viscose rayon, tencel, hemp, basket reed and even silk. These powdered dyes are used at room temperature, 75° - 95° F (24°C to 35°C), using soda ash as the fixative. PRO MX reactive dyes are completely inter-mixable and have excellent wash and lightfastness. They will not work on synthetic fabrics. A two ounce (57 gm) jar will dye approximately 3 pounds or 14 yards (13 meters) of cotton muslin to a medium shade in a solid shade dye bath, or 12 T-Shirts for tie dye. Available in over 135 colors!