EP11: Eva Engelen, HNST, About sustainable dyes & how a start-up doesn’t have to compromise on sustainability

For our second podcast episode, we invited Eva Engelen from HNST Jeans. The perfect guest to talk about sustainable dyes and how you can implement these without compromises.

Dyeing fabrics is a very polluting process. More and more cost-effective, resource-efficient, and sustainable dyeing alternatives that are safe for people and nature are surfacing. But what are these innovative dyeing techniques? How can we lower the true cost of colour? What are the challenges with developing these new techniques and how to overcome them?

Being sustainability & product manager at HNST, these questions are not new to Eva. The steps that HNST has already taken on this topic are an inspiration for the industry.

Listen to the podcast on Spotify.

If there are 5 things you need to take away from this episode, let it be the following. 

​- Find partners who share the same vision and passion as you;
– Have an open collaboration with your partners;
– The biggest challenge is scaling from lab to industrial;
Create products that are sustainable AND beautiful;
– Transparency
: share your failures, learnings, and the steps you still have to take.


HNST is a Belgian circular fashion brand, producing jeans like jeans should be produced by closing the loop. As a sustainability and product manager, Eva Engelen is involved in the creating, making, and sourcing of the products from design to sale. She’s also involved in R&D, constantly looking for new innovative ways to ensure the lowest possible impact of their jeans on the planet. For example, innovative dyeing techniques.

Why jeans?

Jeans are one of the most impactful garments anybody can have in their wardrobe, both societal and environmental. Around 15% of the worldwide pesticide is used for the cultivation of cotton. Next to the amount of pesticide used, the production of jeans also requires a lot of water. Approximately 7000-liter water is used for 1 pair of jeans, which is the same as 9 years of drinking water for 1 single person. Lastly, jeans are designed for a linear life cycle, fated to end up in a landfill or burned.

HNST tries to tackle this challenge by creating circular jeans made from 56% of recycled jeans, containing no harmful chemicals, and saving water. 

To be able to create jeans like this as a startup, you need to set up very good partnerships with every player in the supply chain. HNST had to do the same. The first two years were solely focused on research and development and on finding the right partners who are equally as motivated about circular fashion.

Finding the right partners was one of the biggest challenges for them, as they were coming with a huge list of demands for their suppliers and only limited volumes at the beginning. This made it hard to find partners but eventually, they found suppliers who shared the same vision as them. Now, they are lucky to have built long-term collaborations with their suppliers. By having regular meetups, brainstorms, open conversations, and keeping each other updated on the new innovations they are working on, they keep their supply chain transparent and strong.

Innovative dyeing techniques

​HNST uses a lot of new sustainable dyeing techniques.

For example, to give their jeans a deep blue color, they use a technique called Smart Indigo. Normal indigo dye coloring is hydrophobic, so it does not bond well with yarn. This results in the usage of harmful chemicals and a lot of water to dye jeans. That’s why HNST uses this new way of dyeing jeans, by using electricity to get the indigo to stick to the yarn. No harmful chemicals and a lot less water is needed.

HNST also just came out with a new collection of black jeans called Reblack. For these jeans, they used a circular dyeing technique. After dyeing the jeans, the wastewater gets filtered and the residue from the black dye will be regenerated and can be used again. This way they close the loop in the dyeing process.

Using these new and innovative dyeing techniques does not come without its challenges. Finding alternative and sustainable techniques is not difficult, but scaling these techniques from lab to industrial and making this financially possible is the biggest challenge.

Transparency is a journey 

HNST, the name says it, is a brand that wants to be honest and has nothing to hide. They are transparent about all their partners and every material that is used. They are able to do this because they are working closely with every supplier throughout the supply chain. Of course, they still face challenges and they are not a perfect brand, but the most important part is to communicate about it. For this, they created the ‘hall of fail’, where HNST shares challenges and learnings that they are facing in becoming a more circular brand, to truly be transparent.

An honest future

Eva also shared some of the future plans of HNST, the ones that are not the top secret of course. HNST generally wants to be more in stores all around the world (Belgium, France, Japan,…). So looking to branch out more internationally. They are also doing research to increase the percentage of recycled jeans in their products beyond 56% and looking at how to introduce a stretch that is sustainable. Next to these new developments, they are also introducing more products other than jeans that they produce with the same philosophy and looking to find more colors to add to their collection.

Lots of exciting future plans for HNST on the journey to a better future. Eva Engelen dreams of a future where people live more respectfully to other people and nature, where people are more connected to nature and feel inspired by it. 

A dream that we all share, let’s make this dream our goal. Let’s do great things together!