Woad and indigo Isatis tinctoria

indigo extracted woad

the dye chemical extracted woad indigo, same dye extracted true indigo , indigofera tinctoria, in lower concentration. following european discovery of seaway india, great amounts of indigo imported asia. laws passed in parts of europe protect woad industry competition of indigo trade. proclaimed indigo caused yarns rot: in 1577 german government officially prohibited use of indigo, denouncing pernicious, deceitful , corrosive substance, devil s dye. ... recess of diet held in 1577 prohibited use of newly-invented, deceitful, eating , corrosive dye called devil s dye. prohibition repeated in 1594 , again in 1603. in france, henry iv, in edict of 1609, forbade under pain of death use of false , pernicious indian drug .

with development of chemical process synthesize pigment, both woad , natural indigo industries collapsed in first years of 20th century. last commercial harvest of woad until recent times occurred in 1932, in lincolnshire, britain. small amounts of woad grown in uk , france supply craft dyers. classic book woad woad plant , dye j. b. hurry, oxford university press of 1930, contains extensive bibliography.

a method producing indigo dye woad described in history of woad , medieval woad vat (1998) isbn 0-9534133-0-6.

woad biodegradable , safe in environment. in germany, there have been attempts use protect wood against decay without applying dangerous chemicals. production of woad increasing in uk use in inks, particularly inkjet printers, , dyes. plant can cause problems, however: isatis tinctoria classified invasive species in parts of united states.

the latter refer using glass in tattooing process or scarification. has been claimed caesar referring form of copper- or iron-based pigment.