Dyeing with Avocado and Indigo – Looking at Water Waste in the Dye Process

#HawaiiFiberProject Part III – Natural Dyes

Natural dyes aren’t always the practical choice, but they are certainly an art form. Getting the right combinations and knowing how the dyes will react with fabrics, mordents, and weather is an extensive learning process. Due to the complexities in process and inconsistencies in color, natural dyeing may not be the answer for large scale fashion to become sustainable. To reverse the harm done by this part of the garment industry, we need innovative technologies in dye processes and textile production to address the water waste and chemical pollution caused by modern dye houses. By looking closely at artisanal methods of dyeing, I hope to spark curiosity in finding better solutions. Are there ways to infuse color without wasting water? What about growing materials to have a natural color without dyeing?

Unlike the previous parts of the #HawaiiFiberProject (sakiori weaving and making pineapple fibers) I’m not a novice in natural dyeing. Besides growing up dyeing with Japanese indigo with my Mom and conducting research projects in middle school on how mordents and fabrics impact the dye color, I’ve also taken a natural dyeing course at the Fashion Institute of Technology with Liz Spencer (the founder of The Dogwood Dyer) as part of the Sustainable Fashion Entrepreneurship Certificate. 

This project got me daydreaming and I started thinking, Why don’t I start a dye garden?? Then I snapped back to reality when I remembered that I’m starting a challenging graduate program at NYU, training for the NYC Marathon, and promised myself to consistently write for this blog. Unfortunately I just don’t have the time, but maybe one day. During my time back home in Hawai’i, I did have a chance to experiment with wild indigo and avocado pits. Two materials I have never dyed with before, and two materials you can find growing in Hawai’i.

The Process

I scoured the Waimea nature trail for wild indigo, having only seen pictures on the internet, but didn’t see anything quite right. At least, I didn’t see anything that matched the pictures I saw with enough certainty to merit hurting and picking the plant. I returned with my Mom a couple days later to try again. We were about to give up when we spotted a plant near the end of the trail. There were only a few plants here and there, not the big bushes that they can grow into. We picked what we could get, and hoped it would be enough to dye one tank top. 

After gathering the leaves (and a few seed pods to try and plant later) we got home and immediately prepared the dye bath. With wild indigo, the leaves must be used fresh, otherwise they won’t be effective. We took all the leaves off the stems and tied them up in an old stocking, then left the leaves to soak in water overnight.

Avocado pits were easier to come by. After gathering a couple from the neighborhood, we supplemented them with a few store bought ones, there were eight pits in total.

Now that I had cleaned my eight avocado pits and let my indigo leaves soak overnight, it was time to start dyeing. I went to the local thrift shop at St. James Church and got two tops, one 100% silk tank and one 100% cotton t-shirt. I found another silk top to throw in the mix when I got home. First, I soaked the tops in water with a bit of soap and rinsed them out.

In the meantime I prepared the avocado dye, boiling the pits along with some of the rinds for a little over an hour. After letting the dye pot cool and steep for about another hour I placed the cotton t-shirt inside. I thought this would only take about 10-15 minutes, but I ended up leaving the shirt in the dye bath for several hours hoping the color would get stronger. Ultimately the shirt came out a very light pink, not what I was hoping for, but still nice.

For the indigo tops I submerged them in the dye bath several times for 15 minutes at a time, letting the shirt oxidize in between. I love the pale blue that came out of the wild indigo, it ended up being stronger than I had anticipated, so that was a nice surprise. I tried dying one piece in the indigo and then in the avocado, hoping for a purple color. The color ended up being a light green instead of purple. The original shirt had a yellow tinge and the light indigo color made it green, unfortunately the avocado had little to no effect. 

It was exciting to wake up and see how the shirts dried the next day to view the colors in the natural sunlight. I’m happy with the result, even though the colors didn’t all come out as vibrant as I had hoped for. If anything, it makes me want to try again with different combinations. Maybe I needed more avocado pits? What if I had tried using a mordent?

The Takeaway

It’s a rush to take something from nature, and through a few steps, revive an old garment with a new color. Like the other parts of the #HawaiiFiberProject, natural dying can be extremely time intensive. From foraging for the materials, preparing the dye bath, and the actual dye process itself, this project took me two full days. If I had done any special techniques like resist dyeing or shibori, it could have taken at least one more day. I also didn’t use any mordents in my dye process, which would add a level of complexity. Yet, because I didn’t use mordents I’m a little worried about the color fastness of the dyes. Fast fashion uses a host of synthetic dyes that are made to stay colorfast, withstand multiple washings and high heat. All these qualities come at a price though, these dyes tend to contain carcinogens that enter the waterways if left untreated, causing harm to the communities nearby. 

It’s not unheard of for companies to use natural dyes in their products, but it takes a dedicated and understanding consumer for this to be successful. Natural dyes lose their vibrancy over time and require special care, something many customers have no patience for. It’s also important to question if natural dyeing is truly sustainable on a large scale. Are there better options? Maybe for smaller boutique brands, natural dyes are a viable option. But what about on a large scale? Most of todays clothing is not made in small batches, is there a way to fit sustainable dyeing practices into large scale production? 

Leaders in the fashion industry are starting to emerge with answers to these problems, with reduced water dyeing, or entirely waterless dye processes. Levi’s did a study to pinpoint the best ways to incorporate sustainability along their supply chain, and concluded that the dye process was an area they wanted to focus on. Their Water<less denim line emerged from this research and is committed to using less water in the dye process. Nike and Adidas are cautiously supporting waterless dye technology, with cost being a major barrier. Either the consumer needs to demand these products, or there needs to be breakthroughs in technology to make this a cheaper endeavor. Consumer demand tends to drive innovation and new technology, if there’s money to be made off of it, they will make it.

By cleaning up this area of the garment industry, this would drastically change the game for sustainable fashion. I hope it’s something that people start to think about more when they purchase a new piece of clothing. If a shirt was dyed and finished with harmful chemicals, what does it mean if that shirt is now rubbing against your skin? Is there any impact? And if there is, should we be concerned? My instincts are telling me that we should be.

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  1. Michel Garcia claims that natural dyes should be just as long-lasting as conventional dyes if the process has been carried out correctly. He gets his fabrics tested after dyeing to assess lighfastness and at least one was much faster than commercial dyed fibres. Mind you, he’s a biochemist so he understands process and chemical reactions much more clearly.

  2. Thank you for sharing, Alison! I’ll have to check out his work, I’m happy to learn about new techniques 🙂

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