An outline is given of the sources, heartwood dyes and uses of 19 dyewoods, among them "soluble" redwoods (Caesalpinia spp., Haematoxylon braziletto), "unsoluble" redwoods (Pterocarpus spp.) and logwood (Haematoxylon campechianum). Heartwood dyes are mordant dyes. The application of natural dyes dates back to antiquity, and many of these arose from wood and bark. With the discovery of the Americas dyewoods became increasingly important until 1856, when the first commercially successful synthetic dye was serendipitously discovered by W.H. Perkin. Of all dyewoods only logwood was used as a black dye on silk, until very recently and is still used to dye nylon and as a very important stain for biological work.