The root of <i>Lithospermum</i>, a wild perennial growing in Asia, has been used historically to obtain a deep, mellow purple dye with high colorfastness. The dyeing behavior of this plant was studied for silk relative to dye concentration, a variety of metallic salts used as mordants, a variety of organic chemicals used to extract the dye, and the use of potassium alum, both as a mordant and premordant. -- AATA