Danish researchers have come up with a plan to produce and apply the jeans dye indigo in a much more sustainable way. It appears to be a viable method, they show in Nature Communications.

If any colour is iconic, it is that of jeans, derived from the molecule indigo. This is now widely produced using highly reducing and alkaline substances, which is not good for the health of workers or the environment. Katrine Qvortrup, Ditte Welner and their colleagues at the Technical University of Denmark thought that if they could make this huge industry sustainable, they could have a major positive impact on the world.