For, oh, at least 20 years I wore blue jeans every day (or at least every day that I didn’t have to conform to workplace dress code, and even then I would normally change into them as soon as I got home). Such was their ubiquity I never thought to wonder where they originated from, or indeed, why they were blue. It turns out that they have a much longer, and more interesting, history than I had been expecting…

The story of jeans begins in the textile workshops of Genoa (in what is now Italy) and Nîmes (in southern France). In those trading cities of the 16th–17th centuries, weavers produced a coarse, twill-woven cotton known simply as jean or jeane (or ‘jean fustians’, fustian being the name given to heavy, woven, cotton fabric). The word ‘jeans’ itself almost certainly comes from the French word Gênes, meaning ‘Genoa’. The fabric, and the name, spread quickly – the UK National Archives records that in 1576, a quantity of ‘jean fustians’ arrived into the port of Barnstaple. This fabric, described as being of “medium quality and reasonable cost” was more akin to corduroy than the stuff that we wear on our legs today, and was used for everyday work clothes due to its hard-wearing nature – indeed the Genoan navy was outfitted in jeans material, because it could be worn both wet and dry. 

These clothes were dyed blue, very much like ours today, using indigo dye from the plant Indigofera tinctoria. Indigo had been used as a dye in south Asia for millennia and European colonisation of the subcontinent resulted in much greater commercial cultivation and export. At the same time the colonial powers introduced it as a cash crop in the Americas – with Spain starting to cultivate indigo in Central America in the 16th century, and France on the island of Saint-Domingue (Haiti) in the 17th century. So indigo was cheap, the blue colour helped to conceal stains and also it was more colourfast than other dyes. Indigo is not soluble in water, rather than being absorbed by the fabric fibres it forms a solid layer on their surface – which makes it very hard for it to be washed out. It can though, as you will have doubtless seen, gradually rub off the fibres through wear, a process called ‘crocking’.1

Now you might think that everyone would be happy about this cheap, useful, dye pouring to Europe, but you would be wrong; the woad producers were very unhappy indeed! Woad is a traditional blue dye made from the plant Isatis tinctoria (a member of the cabbage family) for thousands of years. The Roman historian Tacitus famously claimed that the ancient Britons would even use it on themselves:2

All the Britons dye themselves with woad, which produces a bluish colour, and gives them a more terrible appearance in battle.