How sustainable are Fabric Blends and Mixed Fibres ? - A Shift
Fabric Index

Fabric Blends and Mixed Fibres

We have talked about different types of fabrics before but what about two or more fabrics mixed with each other? So-called fabric blends or mixed fabrics are quite common in fast fashion. Why is that? How sustainable are fabric blends? 

From a few percent elastane in our cotton sweatpants to our favourite sweatshirt made from 50% cotton and 50% polyester, wool and acrylic blends and more. If we all combed through our closets right now we would definitely find some pieces that contain mixed fabrics or so-called fabric blends. But why do some of our garments contain blends? Are fabric blends better? How sustainable are mixed textiles? 


What fabrics are usually mixed with each other?

The most common fabric blend is a mix of cotton and polyester. That mixture can either result in a cotton-poly-mix which means there is more cotton than polyester used in the blend (e.g. 51% cotton, 49% polyester) or poly-cotton-mixes which is the other way around. Often you can also see that your garment is exactly made of 50% of each fabric. Other common blends are cotton mixed with some elastane or spandex, wool mixed with cotton or synthetic fabrics like acrylic and completely natural blends like cotton and linen or cotton and silk.The options seem to be endless. 

Why are fabrics blended and mixed?

Fabrics are usually blended or mixed with each other to make a garment piece more durable. For example blending cotton with polyester is said to combine the two fabrics’ best features while countering their weaknesses. On top of that it is also cheaper to blend natural fibres with synthetic fibres like polyester as they require less resources. That is why you generally see more synthetic fabrics in the fast fashion industry instead of natural mono-fabrics – 100% of one fabric – since they cost less. 

What are all of the benefits?

There are different and multiple benefits to blended fabrics. We have already talked about countering weaknesses and improving the best properties of each fabric of a blend to create the ultimate fabric. However, there is more. Blending materials can also improve the texture or appearance of a garment. On the producer’s side or let’s better say the fashion brand’s side the benefits are that blending fabrics is also cheaper and sometimes makes the spinning process more efficient

When it comes to cotton and polyester blends the end result is usually more durable and therefore said to be longer-lasting. Why, you ask? For example, cotton shrinks more easily while polyester doesn’t. Cotton also wrinkles more easily while polyester doesn’t. On the other hand cotton is breathable while polyester is not. Blending the two reduces these disadvantages. Additionally, for consumers this type of fabric mix is usually more affordable since it is cheaper to produce. However, when it comes to the environment synthetic fibres are an issue. Even if they are recycled.

Are mixed fabrics sustainable?

How sustainable are fabric blends? Due to the fact that most fabric blends contain synthetic fibres they are usually not sustainable. When it comes to natural blends the good news is that natural fabrics are biodegradable and have less of an impact on the planet. However, it also depends how fabrics are dyed, if they are organic, who made them in what circumstances and many other factors. Even cotton as a mono-fabric can have a negative impact on the environment and the people producing it. Although it can be said that cotton-polyester-blends are more durable there is a high cost for our environment due to synthetic fabrics being derived from fossil fuels. Natural – preferably organic and certified –  mono-fabrics are always the most sustainable option. 

Microplastics and fossil fuels 

The addition of synthetic fibres to natural fibres creates many different issues. The first one being that fossil fuels are generally the biggest culprit when it comes to pollution. Next to that, polyester and other synthetic fabrics – yes even recycled ones – release microplastics into our water. What are microplastics? Microplastics are small particles of plastic for example from textiles that are being shed with each wash cycle. Did you know that just a single fleece jacket can shed up to one million microplastic fibres while being washed? These microplastics are harmful to our marine life including animals and plants. On top of that, there is also a potential danger for humans, but according to the UN the amounts we consume through sea food is negligible. We have talked about the dangers of microplastics here if you would like to read more about it.

Recycling fabric blends 

Now we are getting to one of the biggest issues surrounding fabric blends: recycling them. It is far more difficult to recycle fabrics that are mixed or blended as they are harder to seperate. Especially if natural biodegradable fibres are mixed with synthetic fibres. The end result is a yarn mix that cannot be recycled anymore even if the amount of synthetic and therefore non-biodegradable fibres is kept to a minimum. Moreover, a 100% cotton shirt has labels and sewing threads that are often made from polyester. So, even separating these ‘easier’ components can be quite labour intensive and therefore more costly. However, when it comes to fully natural blends the upside is that the garments are biodegradable.

Luckily, there are new innovative materials like biodegradable alternatives to synthetic and elastic fibres and new technologies that can separate blended cotton and polyester yarn. However, it should be noted that the cheapest option is still to use virgin material blends that contain synthetic fibres. On top of that, recycled polyester that is used in fast fashion mostly comes from recycled PET bottles and not from old clothing which further proves the point. Unfortunately, despite the urgent climate crisis we are in fast fashion brands have not adapted in a timely manner and it is questionable if they will if they don’t see immediate profit.

So what is the verdict?

All in all blending fibres – especially natural fibres and synthetic fibres – can be harmful to our environment as they are difficult to recycle and separate. Further, synthetic fibres and sometimes even natural fibres like cotton are generally not sustainable. While this is cheaper for fast fashion brands and therefore more affordable for consumers we have to keep in mind how destructive blends can be to our environment. This is especially an issue since old clothing is often not recycled and instead PET bottles are used which leads to more and more clothes ending up in landfills. 

Of course it is understandable that many consumers cannot afford sustainable and more expensive clothing. However, we as consumers need to demand more from fast fashion brands. From mentioning brands in our social media posts, to emailing brands and putting our money where we see fit. There are many different ways to explain to or show brands how we feel as consumers and what we demand. On top of that, we can use the Guppy Friend – a washing bag that keeps the microplastics inside so you can throw them away after. This is a big step to reduce the impact of the mixed fibres pieces already in your wardrobe. When shopping in stores or online always make sure to check the labels so you know what is inside of the piece you want to purchase. Going for mono-fabrics is definitely the way to go and in the meantime remember we can demand big brands to be more sustainable now, not in 2030 or 2040.