Yamato Indigo is indigo powder dye developed by Aikuma Senryo, a company founded in 1818 in Tokyo. The company was originally a Chinese herbal apothecary and later began supplying dyeing supplies. In the 1870’s, when indigo was exceptionally valuable, Aikuma Senryo developed a method for extracting the indigo pigments from old indigo-dyed fabric. By boiling the fabric in water, a clay-like dye called airou(indigo wax) was created. Airou became a popular option for dyers until synthetic indigo eventually became available in Japan. Based on this method of making airou, Aikuma Senoryo created Yamato Indigo, a powder dye consisting of extracts from indigo plants, chemical indigo, alkaline agent, and reducing agent.