Natural Dyes in Sustainable Denim, Explained

natural denim

We love denim, jeans, jackets, skirts, and shorts can all look amazing in the hard-wearing French fabric.

However, there is a question that’s been nagging at us, while we know that cotton can be sustainably farmed to make denim, what about the dyes in denim?  Can they be sustainable too? So, we investigated and this is what we found.

Indigo The Dye For Denim 

To get the bright blue of denim, you need a dye that provides that particular hue and nature has only one dye to offer in this respect; Indigo.

It’s derived from the Indigofera, a planet which is from Asia (or possibly Africa) and which has been farmed and cultivated for many thousands of years specifically for its properties as a blue dye.

Indigo is something of a miracle as dyes go.

When you use it on cloth, it adds flame-retardant properties, acts as an antibacterial agent and makes it hard for both dirt and odors to get a hold on the fabric.

This is one of the reasons that it was chosen to dye denim originally. 

Denim was worn by factory workers and these properties meant that it could be worn, quite literally, for months without being washed. 

Denim was so ubiquitous by the 19th century that the working classes everywhere wore it and the term “blue collar” is derived from it. 

Why Is Natural Indigo Important For Sustainability?

Natural indigo, however, is something of a pain to harvest and the dye takes a while to produce.

You have to pull the leaves, soak them, ferment them, dry them, press them and then turn them over to artisans to carry out a long and complex dyeing process with. 

This kind of labor demand led to a huge demand for synthetic alternatives and the industrial revolution provided it.

sustainable jeans

Unfortunately, the synthetics are terrible for both people and the environment and can contain cyanide, formaldehyde and other toxic chemicals.

This, in turn, has seen consumers begin to demand a return to natural indigo from the industry.

This is good news for fashionistas, mind you, as the natural indigo dye is much bolder blue than can be produced with a synthetic dye and it should be clear to the naked eye who is wearing sustainable denim. 

Indigo’s replacement with synthetics was an obvious consequence of the rigmarole required to extract the blue dye but in recent years consumer demand has switched to sustainable denim and indigo is making a comeback. Fortunately, with improvements in modern engineering, it’s no longer such backbreaking work to harvest and process indigo.