Indigo has been used since ancient times. Until recent times, it was considered the epitome of colorfastness, and up until the early years of this century, the most renowned chemists and dyers were involved in developing new methods for applying this dye in dyeing and fabric printing. However, over the last few decades, this dye has nearly lost its significance, following the discovery of a large number of significantly more colorfast dyes in various shades. It has now been half a century since RENE BORN invented Indanthrene Blue, the first synthetic dye that does not occur in nature. The first half of this period saw the discovery of all the important synthetic dyes currently in use. During the second half of this period...