William Morris's essay on dyeing as an art, contrasting traditional natural dyeing with the commercial aniline dyes that he argues have nearly destroyed it. He describes the four base colours (blue, red, yellow, brown) and the dyestuffs for each: indigo and woad, kermes, cochineal, madder, weld, walnut and catechu. He also covers mixing for green, purple and black, the difference between substantive and mordant (adjective) dyes, indigo vat practice, alum mordanting, and the fading of dyes as seen in Gothic tapestries.