Basic Information
Isatis Tinctoria is a yellow flowering plant, native to Europe and related to cabbage and mustard. When the leaves of the plant are dried, powdered and fermented, they create a blue dye called Woad. Woad was used by the Celts as war paint and in tattoos. Other civilizations used woad to dye cloth, from the vikings to most of Europe into the Middle Ages and right up until synthetic dyes replaced it relatively recently.
Indigo dye comes from the closely related Indigofera tinctoria plant, which the Portuguese began importing from India in the 15th Century. This threatened the local Woad economy, so Indigo was outlawed (on pain of death!) in Germany in 1577 and in France in 1609. These Sumptuary Laws called it "the devil's dye" and "the Indian drug" respectively in an effort to discourage it's use. (Sort of a colorful early example of Yellow Journalism.) Ironically, the blue dye of Woad is chemically identical to Indigo, just at a lower concentration of pigment.
As a blue pigment, woad may well have been used to color blue jeans in the 17th Century - see Master of blue jeans holds key to fashion riddle
Sources
Game and Story Use
- Woad is an important part of the color and theming of Celts, so it's likely to show up in historical games set in Europe. An army of Celtic warriors literally blue-in-the-face, and sometimes naked, tattoo'd, and with spiked bleached hair can be a very intimidating sight.
- Perhaps so intimidating that you break out the psychology rules for inflicting fear on the opposition.
- Woad could be blueprint (forgive the pun) for a unique plant dye in your setting. Perhaps it has magic properties or special meaning for a particular culture or species.
- The Woad-vs-Indigo conflict could inspire crazy protectionist sumptuary laws in your setting. True patriots only use clothing dyed with local flowers, not those terrible imports!