Introduction Purple dye Sea snail purple, also known as Shellfish purple, Tyrian purple, Royal purple, Ancient purple or Murex purple, abbreviated to purple in this text, is a pigment obtained from the secretion of the hypobranchial glands of certain species marine mollusks (Fig. 1). The milky secretion from the glands includes a purple precursor which can be applied directly onto textiles (Fig. 2), where the final pigments are formed in the presence of oxygen and sunlight (Fig. 3). The main chemical constituent of the purple pigment was discovered by Paul Friedländer in 1909 to be 6,6′- dibromoindigo. Purple dye in Central America Purple has been used for dyeing of traditional textiles in Central and South America. It still continues to ...