Sappanwood

This rather uninteresting-looking rusty powder is a red vegetable dye called sappanwood that comes from the heartwood of the South and South East Asian tropical hardwood tree Caesalpinia sappan. There is archaeological evidence of sappanwood’s use as both a dye and a medicinal substance from the 2nd Century BC onwards in Asia. It became a very important dye in Japan in 820 AD when the Emperor decreed that the colour koro (the colour of sappanwood-dyed silk) was the official colour of Japanese ceremonial costumes. By the Middle Ages in Europe, cheaper and more robust sappanwood dye was competing with crimson and scarlet dyes from insect-derived dye kermes and the root-based dye madder, and it remained a very important red dye in Europe up until the 16th century.

Sappanwood is almost indistinguishable by lay people from another related hardwood species contains the same red dye-producing compounds, brazilin and brazilein: Brazilwood or Pernambuco (Caesalpinia echinate). Brazilwood is perhaps the only wood that was historically so culturally and economically important that it was responsible for the naming of an entire nation. When the Portuguese first colonised Brazil in 1500, their traders found it to be full of trees that could be used to produce a very sought after and robust red dye called ‘brasil’ (derived from the Portugues word ‘brasa’ which means ember) that had previously been extracted with great cost and effort from Indian sappanwood trees. This dye-rich country became known as ‘Terra do Brasil’, which got shortened over time to Brazil.

However, brazilwood has historically been so overexploited for dye production and the manufacture of bows for stringed instruments (violins, cellos etc.) that it is now listed as an endangered species, with its international trade heavily controlled as a result. Unfortunately sappanwood and other alternative dense tropical hardwoods don’t have quite the same acoustic properties as brazilwood – particularly its ability to preserve the vibrations created when the bow is drawn across the strings – creating an ethical dilemma for bow makers. The low ‘loss factor’ of brazilwood is thought to be related to its particularly high brazilin content: the same property that makes it so valuable as a source of red dye. Researchers have attempted to impregnate other woods like spruce with brazilin and the other resinous compounds in brazilwood, thereby slightly improving their sound-carrying properties.