INDIGO … the true blue

Our June meeting this year fell on the weekend of  the Queen’s Jubilee celebrations, so we decided to do something different and  some of us gathered to experiment with  an indigo dye vat and share a picnic.

In these days where everybody (except me!) has a pair of blue jeans the colour is very familiar but indigo dyeing has been around for thousands of years. Before the invention of synthetic dyes, if you wanted your toga or whatever to be a different colour, you’d have to go find something in nature to dye it with, maybe mud, a mineral, an insect or the seed, flower, root or leaves of a plant.

Applying wax before dyeing

Lynne and Joan G prepare their wrapped pieces

Indigo is said to be one of  the oldest dyes, with cloth found in Egyptian pyramids and Ancient Peru. Ancient civilizations used indigo as more than a fabric dye. They used it in cosmetics, paint, crayons, and more. The blue dye is extracted from the ‘indigo fera’ plant- a family of roughly 750 shrub species found in tropical and sub- tropical regions of the world. The word indigo traces its origins from the Greek word ‘indikon’ which translates to ‘Indian’, indicating India to be a prominent source of indigo for the Greeks. However, it was also naturally cultivated in diverse areas like China, Japan and Egypt. In Europe the ‘Isatis Tinctoria’ plant was used to produce the blue colour known as ‘woad’ or ‘false indigo’.

Bundled pieces on the line awaiting dipping

Chatting and dipping

Now ubiquitous, indigo was once a highly prized pigment available only to the rich and powerful. Aptly referred to as ‘the blue gold’ the demand for this vegetable dye fuelled several trade wars. It also enriched many empires and left an indelible mark on the histories of many colonies where it was cultivated.

Italian merchants first encountered indigo during the Crusades in the flourishing markets of the Middle East, who in turn obtained the dye from East Asia. The Italians started importing large  quantities of indigo to Northern Europe. The Indian indigo was found to be of a far superior quality than the local woad. Needless to say, local woad producers felt quite threatened by this hugely popular import and labelled it as ‘the devil’s dye’.  Over time Genoa became popular for its tough, rich blue fabric that was found to be an ideal workwear for miners, fishermen etc. French being a commonly spoken language in Europe during that time, this sturdy cloth came to be called Bleu de Gênes or the Blue of Genoa. This term would later turn into the word jeans in English.

Jo and Joan B at the vat

Joan G and Kate at the vat

The Blue of Genoa also reached the French city Nîmes known for its exceptionally talented weaver community. These weavers sought to create their own version of the indigo dyed cloth. Several experiments later they were able to create a similarly strong blue fabric. The warp yarn was treated with the indigo dye while the weft yarn stayed white. The result was a fabric that had two strikingly distinct surfaces. The deep blue surface of the cloth was kept facing the outside with the white/faint blue surface on the inside. It became roaringly famous due to its exceptional durability and was named de Nîmes or denim in English. Indigo dyeing had truly come full circle from producing fabrics that only the affluent elite could afford to robust workwear for the masses.

It takes at least 100 pounds (45 kg) of plant to make 4 ounces (113 g) of dye. This made it a very valuable commodity. Indigo plants consist of a solitary stem which supports oval, deep green leaves and clutches of red flowers. The dye is obtained from the leaves through the arduous and smelly process of fermentation. This is  quite a delicate process and there is a lot of scope for things to go wrong. This led the natural dyeing process to become surrounded with many superstitions, for example, in some places like Eastern Indonesia it began to be seen as a sacred activity that only women were permitted to carry out –  men were prohibited from even looking at the indigo vats.

Joan B waiting for the green to oxidise to blue

Adding to the vat

The harvested indigo crop would be submerged in huge containers filled with water. Wooden logs would then be put on top of these containers to thoroughly press the crop inside. This would initiate the process of fermentation- the water would begin bubbling and turning blue. This blue liquid was then drained into another container to separate out dirt and other debris that might have got into the mixture.

This repulsive smelling blue water was then mixed around with specially constructed paddles to further separate the plant from the pigment. Now a third container was employed to store this clear blue liquid. It was allowed to sit in here till the indigo contained in it settled down. Then the water was drained out and the indigo set aside to dry. The final products were small blue objects which could be grated to get the wonderfully blue dye.

Sitting on the step to undo stitching

Needless to say, our day did NOT begin with collecting leaves from indigo plants!!

Phoenix member Rosaline Darby generously organised the buying of indigo and a large vat and setting it up for us to dye our pieces. We donned our old clothes, aprons and rubber gloves to see how the magic worked! Damp fabrics needed to be carefully lowered into the vat to avoid excess oxygen mixing with the liquid. It is oxidisation that makes the ‘magic’ as items soak up the green liquid but quickly turn blue when they are removed and come into contact with the air. The fabric needs to stay in the dye for 5-10 minutes and we tied string around the pieces so that we could suspend them over the vat. Using carefully gloved hands the fabric is squeezed gently under the surface to encourage the dye to penetrate. Care is also needed to extract the pieces without too much disturbance.

The length of time in the dye determines the depth of the blue shade and pieces can be re-dyed if you want to make the colour deeper. Most of us made patterns by adding resist in some way. Wrapping with string produces a ‘tie-dye’ effect, folding the fabric with clips to keep the folds in place produces lines of colour. The fabric can be stitched in various ways with a strong thread so that the dye penetrates unevenly. Anyone familiar with Japanese shibori techniques will know that amazing patterns can be produced. Wax can also be used to resist the dye and then removed later by ironing. After dyeing the pieces are then rinsed in water with added vinegar to  neutralise the alkaline soda ash that is in the dye bath. After another good rinse in clear water they can be hung out to dry!

Our finished washing line

Nowadays of course indigo is mostly manufactured synthetically. It wasn’t until
1856 when a teenage British chemist named William Perkins accidentally formulated the first synthetic dye. A breakthrough came in 1870  when German chemist Adolf von Bayer managed to produce artificial indigo. He perfected his technique and in 1897 sold the formula to the German chemical company BASF. The natural indigo dyeing process is becoming rarer and rarer now. There are now only a handful of producers who provide natural indigo dyed fabrics, with most of them found in Brazil, Indonesia and El Salvador. Almost all our denim clothes are dyed using synthetic indigo which gives it a darker blue shade. Compared to natural indigo, synthetic indigo is purer, cheaper and gentler on the environment. During an excavation in Thebes, Greece, an indigo cloth was discovered. It is thought to date back to 2500 BCE. It seems like our current love for indigo has very deep roots!

Jo’s finished pieces

Maria’s finished pieces

Kate’s finished pieces

Joan G’s finished pieces

Although, given that it takes approximately 1,800 gallons of water to grow the cotton for a pair of blue jeans, perhaps we need to keep thinking carefully about the environmental damage to the planet of everybody’s favourite garment!

End of an enjoyable day

Thanks to Joan Bingley for the use of her garden and barn, to Rosaline Darby for the dye preparation and to Linda Walsh for the research and compilation of this article.

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