In prehistoric times woad was a native of southeastern Europe, presumably either around Greece and Italy or southwestern Russia, and spread quickly throughout Europe. This plant (leaves) became the dominant blue dye in Europe, especially in western Europe. 'Indigotin' is the blue precursor found in the woad plant and has the same make-up as that found in true indigo (Indigofera Tinctoria). Various shades ranging from the palest to richest darkest blue can be achieved in the dyeing process. A pale pink can also be extracted from the woad leaves when all the blue has been removed.

To make the dye, young leaves are picked, placed in a jar and covered with near boiling water. The jar is covered to ensure that the air is excluded. The liquid becomes coloured and produces small bubbles. Alkali is added to the coloured liquid, and then the solution is shaken until it becomes greenish. Woad is a tricky dye to get correct, and many do not have success even following the detailed recipes that exist. Fabric is dyed greenish-yellow but turns blue when exposed to the air (air oxidation) and becomes relatively fast when put in an acid and then a soapy rinse.