Now that the U.S. Food and Drug Administration has banned Red Dye No. 3, artificial food dyes are under increasing scrutiny.

"The three plants form the basis for primary colors. They were often combined to make other shades like green, orange, purple ...

Woad has been grown for centuries in Great Britain and prepared for market as a mordant or fixer for indigo dye. Its use in dyeing requires much skill, and its preparation is a lengthy process.

botany and chemistry of the plant and the dye, and the object of the paper was to place on record information as to the technology and the cost of the preparation of woad. Fortunately, on farms at ...