Works beautifully on many washable fabrics including: Natural fibers, such as cotton, silk, and linen Synthetics such as rayon, nylon, and acetate Blends will tint evenly but will not achieve full color. For maximum coverage, use the washing machine technique. One bottle dyes 2 lbs. dry fabric or 1 pound of fabric for dark or bright dye colors. Not recommended for 100 polyester, 100 acrylic or fabrics with special finishes, rubber backing, washable only in Cold water, or labeled Dry Clean Only.