Procion MX dyes are "cold water dyes" that are fixed chemically instead of with heat. This unique property sets Procion MX apart from all other dyes and establishes them as the undisputed king of backyard dyeing, batik and tie dye. Because Procion MX dyes can be used away from the stovetop, they are also the ideal colors for shibori, ice dyeing, tub and low water immersion dyeing, printing, direct painting and other "alternative" dye applications. As a fiber-reactive dye, Procion MX forms a strong covalent bond with cellulosic fibers, making it the most permanent and washfast of all dyestuffs. Mix the concentrated dye powder with tap water to create the most vibrant colors possible for cotton, linen and other plant-based fabrics (may also be used with protein fibers if acidified). Procion MX dyes are typically used with a soda ash fixative, which can be added directly to the dye bath or used to pretreat the fabric as in tie dyeing and other "batch setting" techniques. Typically, one 2/3 oz/18.71 g bottle will dye more than 1 lb/0.45 kg of dry fabric (very bright colors will require more dye and pastel colors will require less).