Brazilin

Brazilin is a natural red dye and pigment derived from the heartwood of the tropical tree Caesalpinia sappan, commonly known as sappanwood. It is one of several natural red dyes historically produced from the wood of select Caesalpinia species. The dye consists mainly of brazilin, which can be partially oxidized to brazilein, yielding a related red-to-orange hue. In solution, color intensity and shade depend on pH and the use of mordants.

Extraction and preparation: The wood is boiled in water or extracted with alcohol to release brazilin; the dye is then concentrated and can be used as a dye-stuff or pigment.

Applications: Brazilin has been used for dyeing textiles such as silk and wool, and sometimes cotton, typically with mordants such as alum or tin to improve fastness and alter the color. It has also been employed as a wood stain, ink component, and in traditional cosmetics in some cultures.

History and current status: Sappanwood dyeing has a long history in Asia and Europe, particularly before the advent of synthetic red dyes in the 19th century. Today, natural dye revival efforts include brazilin, though supply depends on sustainable sourcing of sappanwood; modern usage often combines brazilin with other natural pigments or mordants to achieve a range of reds.

Chemical safety and ecology: Brazilin is a natural product; handling typically requires standard precautions. Ecological concerns include overharvesting in wild populations; cultivation and sustainable harvesting practices are emphasized in some dye communities.