Acetate is a silky looking synthetic fabric used in clothing manufacturing and certain home furnishings. Acetate needs special care and handling due to the composite makeup of the fabric. Acetate is made from cellulose and closely resembles rayon in appearance and touch. The fabric is not very absorbent and loses tensile strength when wet. Acetate-based clothing is usually dry cleaned only and but you can wash knits in warm water and lay them flat to dry.
Check the label and determine if it is safe to self clean the garment. If the label reads "Dry Clean Only" then it is not safe to self wash. Certain materials and chemicals, such as nail polish remover and perfumes, will damage acetate and are not removable.
Turn the garment inside out. Using warm water and a small amount of non-bleach, fragrance free, detergent gently rub the stain in a circular motion. Reverse the garment and gently wash the stained area on the other side.
Line dry the item away from direct sunlight or heat. When using the line do not use clothes pins, instead drape the garment over the line. If possible lay the item flat on a drying rack in a cool airy outdoor setting.