Which Fabrics Are The Most Sustainable?

Which Fabrics Are The Most Sustainable? | Curiously Conscious

Is there time for one last sustainable fashion guide before the holidays? I think so. One of the questions I’m asked the most is “which fabrics are the most sustainable?”, especially when buying second-hand garments or clothes swapping. While I sometimes will list out favourites (organic cotton, linen, wool), understanding sustainable fabrics is actually a little more complicated than that.

I hope this guide will help you in discovering which fabrics are the ones you want to go for (and if you do have questions, please leave a comment!)

A Note on Sustainable Fashion, Consumption & Materials

I believe sustainable fashion encompasses four key points:

  • Ethical manufacture – fashion made by people who are treated fairly, with respect, dignity, and are paid well
  • Sustainable manufacture – fashion made from sustainably-grown or recycled materials, using low-impact processes
  • Quality and longevity – fashion that is made to last, and be loved for years to come.
  • Circular processes – fashion that can be reused, reworn, recycled, and essentially stay out of landfill for as long as possible.

Of course, there are other facets to that, and I imagine you’ll have things you look for when buying sustainable fashion. (And as always – don’t buy things needlessly. As the fantastically cringeworthy Will.I.Am says, it’s not waste until it’s wasted…)

Defining what matters to you is something I encourage when switching to ethical fashion. I don’t mind wool, for example, but if you’re vegan, it’s a no go.

And when it comes to defining which materials are sustainable, we need to look at all three of the above points. Natural materials are great, but they may not always be grown sustainably, nor do they all last a long time. Long-lasting materials are also great, but often synthetic. And in either of these scenarios, items could be made using nasty chemicals or in unsafe conditions, which isn’t great for people or planet.

Sigh. It’s never easy, is it?

That said, I’ve made a list of the materials I look for when I shop, and listed their pro’s and con’s for each, so you can decide which are the ones for you…

15 Of The Best Sustainable Fabrics To Look For in Fashion


Linen is a natural fibre, and one that has been used in clothes making for thousands of years. Coming from the flax plant, it takes months to grow, treat, and process until the grass-like fibres are soft and supple enough to be woven into clothing.

This video shows how it was done traditionally in the UK (by a sweet older gentleman!), but nowadays it’s done by machines. Linen can be grown in many different climates, and often doesn’t require pesticides to grow.

I love linen. It holds its form so well, as demonstrated in my (gifted) LF Markey Olaf Shirt* here. It’s also incredibly strong and that makes it great to wear over and over and over. This is reflected in its higher price as a fabric, but over time it’s actually quite affordable. And with designs like this shirt, and my Son de Flor dress, I genuinely want to wear it over and over!

Organic Cotton

Next up, organic cotton. This is one of my favourite fibres as it’s so soft and versatile, but there is a huge sliding scale of impact when it comes to cotton.

Cotton on its own is a tricky fabric to label as sustainable because it takes SO MUCH WATER to produce. A simple white t-shirt and a pair of jeans can take 20,000 litres of water to make – that’s 13 years of drinking water! Cotton’s thirsty nature has been known to cause environmental disasters such as the draining of the Aral Sea.

Cotton may also be grown with pesticides, and/or treated with known human carcinogens. It’s why I recommend organic cotton garments over standard cotton alone. Alongside looking for organic certification of cotton, check out:

  • Cradle-to-cradle cotton garments, which certify its low impact production and biodegradability
  • Closed-loop water systems used to grow cotton and reduce water usage and wastage
  • Better Cotton Initiative mark, which promotes more sustainable farming but is quite loose in its work
  • Fairtrade mark, which guarantees ethical treatment of cotton farmers

My friend and ethical fashion aficionado Ruth MacGilp goes into the issues with cotton in greater detail, or check out my guide to organic cotton for further info.


So, I basically live in denim. If I’m not in a skirt, I’m in jeans. They’re just so easy to wear! But did you know, there are more pairs of jeans on the planet than there are people? That’s a lot of denim. And denim is made from cotton, which means that’s millions of litres of water spent on making jeans…

I wrote a guide to sustainable jeans and denim a while ago which really goes into this, but the main things to consider when buying sustainable denim are:

  • Go for jeans made using closed-loop water systems (saves 1000s of gallons of water)
  • Go for jeans that promote circularity, such as using a percentage of recycled fibres, or ones that can be mended or sent back for recycling
  • Avoid stonewash (is often created using toxic chemicals, see the film Riverblue for more info)
  • Avoid rips and tears (can deteriorate more quickly than regular denim, as noted in the Fixing Fashion Report)
  • Have only one or two pairs of jeans, and wear the hell out of them

I find it tricky to buy jeans second-hand (still searching for the perfect pair of Levi’s!)

Peace Silk

Sustainable fabrics are still being innovated! Peace silk is one such fabric. Did you know, traditional silk is made by insects? Silk is made by silkworms when they make their cocoons, which are then collected by hand, boiled, and spun into threads. Yes, you read that right – the boiling process kills silkworms in their cocoons before they’ve developed into moths. And it takes around 5,000 silkworms to make a pure silk kimono… So it’s not a vegan material, nor a cruelty-free one.

Peace silk is a relatively new answer to this. Silkworms are given the time to develop into moths, and their empty cocoons are then collected to create peace silk. It’s what my beautiful (gifted) Zavi Marrakesh Shirt here is made from – and it has that same gleam and gloss as regular silk!

On top of this is the change in softness: there’s no denying that silk is such a beautiful, glossy material, while peace silk is a slightly more coarse affair.

If you’re super interested in silk, The Fashion Common Room has a great guide which goes into much more detail, and covers even more silk-like fibres, such as hemp silk, lotus silk, orange fibre silk, and soy silk!


If you’d prefer a vegan, silk-like material that’s much more widely available, cupro may be your answer.

Cupro is a circular fibre, meaning it has been made from recycled garments. It is a rayon fibre made from cellulose (usually cotton) that is dissolved in cuprammonium solution.

Now, the last part of that process is the troubling part – cuprammonium requires copper, ammonia, and caustic soda, which can be harmful to workers and toxic when they’re not disposed of properly.

However, when made responsibly, cupro is a great alternative to silk. It’s fine, sheer, and can feel soft to the touch. It’s a step in the right direction when it comes to recycling, but it would be great to see the chemical process changed in the future.

Wool & Cashmere

Another natural material, and another one with issues! I personally love wool, as it’s grown naturally by sheep, goats, alpacas, etc. and creates really warm, high quality clothing. It’s also biodegradable (just ensure it’s not blended with plastic-based fibres). But when it comes to putting it in the sustainable fabrics list, there’s a few things to consider first:

  • Treatment of wool-growing animals
  • Higher emissions associated with cultivating wool (compared to plant-based materials)

While I believe there are a number of ethical knitwear and wool brands out there that treat sheep well and produce their clothing sustainably. However, I do understand that the welfare of animals is important, and often hard to verify. If you’re vegan, or unsure, I’d recommend avoiding it.

A Guide to Eco Swimwear | Curiously Conscious

Recycled Nylon (aka Econyl)

Now we come onto recycled fibres, and the only oil-based material on this list. Nylon is made from oil, and is a plastic fibre. However, for certain garments such as swimwear, it’s an incredibly useful material and one that is difficult to avoid altogether.

That’s where recycled nylon comes in! Made from recycled plastic (often plastic bottles, fishing net, and other easily-recycled plastic items), it’s the sustainable answer for bikinis, rainwear, and other items too. Just make sure to use a Guppyfriend Wash Bag* if you’re washing nylon garments to prevent shedding microfibres from entering our waterways.

Bamboo / Ecovero / Lyocell / Modal / Tencel / Rayon / Viscose

I also wanted to include tree-based fabrics in this list, and my goodness there are so many of them! Put simply, all of these fabrics are derived from tree-pulp, and then processed chemically until they become soft, wearable fibres.

Some of these are better than others – in my bamboo underwear review, I noted that both lyocell and rayon are made from bamboo, but one is treated with harsher chemicals than the other, and often these chemicals end up polluting waterways. I’m no closer to really deciding what is best, but they are potentially more sustainable than plastic-based fibres.


And of course, I couldn’t forget hemp. Yes, it is the stereotypical hippy-dippy fibre that people tend to think of when they hear ‘sustainable fashion’, but aside from that, it’s on-par with linen when it comes to its sustainability credentials.

Hemp has been grown and spun into fibre for thousands of years. It grows fast, can be grown in the UK, and has so many uses – I recently switched to hemp milk and hemp oil, for example! Pure hemp fibre has a very similar feel to linen, although it is often mixed with cotton or lyocell to produce a softer fabric.

Bonus: 7 Not-So Sustainable Fabrics To Avoid

As an addition to my list of good fabrics, I also wanted to list out a few of the materials I avoid:

  • Acrylic
  • Elastane (a.k.a. Spandex or Lycra)
  • Nylon
  • Polyamide
  • Polyester
  • Polyurethane
  • Sequins

All of these are made using oil (yes, nasty petroleum) which means they’re made from fossil fuel, extracted from the ground often in a catastrophic way, processed into a plastic thread, and then woven into wearable fabric. When they’re washed, the shed microfibres. And when they’re thrown away, they take hundreds of years to degrade. Avoid, avoid, avoid.

Disclaimer: This post contains gifted items (denoted 'gifted') and affiliate links (denoted '*')


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