Logwood

The Plant
Logwood, haematoxylon campechianum, is a legume, a member of the pea family. It is a tree that grows up to fifteen meters high and has thin, smooth bark with thorns. It is a hard wood. Unlike most wood, logwood sinks in water. With older mordanting methods, logwood was not incredibly light fast, and fell out of favor for a long time as a dye. However, it was a cheaper alternative to indigo, and historically became popular in commercial dyes, despite fading. It is still not considered light fast, but it does fade fairly true, becoming lighter and slightly greener with time. Logwood produces red, purple, blue, and black colors. The extract was once used as a pH indicator. Brownish when neutral, it becomes yellow-reddish under acidic conditions and purple when alkaline.

How to Harvest
Logwood is an imported natural dye originating in Mexico. The dye is derived from the heartwood of medium to large old-growth trees, originally found in the tropical forests. There are certified organic, fair trade, sustainable sources available.

How to Extract Color
Logwood chips can be soaked directly or placed in a nylon stocking and soaked in cold water for at least an hour. After soaking, the solution should be purplish red. If it is brown, it is too acidic and wash soda can be added a teaspoon at a time until it achieves the appropriate color. Then simmer for one hour. Afterward, remove the stocking or strain your dye bath. Logwood is extremely sensitive to pH. Tin as a mordant will give pinks, purples and maroons. Alum produces blues or blue greys. Do not use cream of tartar as an assistant as this will turn the dyebath acidic and it will take on a brown colour. Copper produces dark blues. Mordant is essential when dyeing with logwood. Color is not light fast. . The dyebath may degrade if kept for a long time and produce greys rather than the expected colours.