"Alizarin is one of two main dyes, the other being purpurin, that come from the roots of the madder plant. It was used to dye cloth in Asia in ancient times and in Egyptian textiles as early as 1600 BC. Its first known use on paper is much later, in 972 AD, when it was used as ink on the marriage certificate of the Byzantine Empress Theophano. It has been used in painting since the 16th century."
