Don’t want no slubs? How to pick high-quality natural fibres

By looking at the weight, texture and composition of fabric, you can tell a lot about the quality – and environmental impact – of a garment or home textile

When I’m looking at a garment, the first thing I do is rub the material between my fingers to see what it feels like. Then I check the care tag to find out what the fabric is made from.

I do this because I can tell how a garment made from natural fibres like cotton, linen, wool or silk will breathe, or provide warmth, based on the composition of the fibres, the weight of the fabric and the density of the knit or weave.

What’s harder to know is how sustainable the materials are. To truly understand textiles’ environmental impact, you have to know what is happening on the landscape where the material was farmed. This requires more advanced transparency and traceability than most designers offer (even though earlier this year FibreTrace offered brands free access to its platform).

While those details require more of a deep dive, you can at least make a start on decoding the sustainability and quality of natural fibres by examining the texture and the label. Here, we explore how to get started. We will look at manmade materials in a second instalment.


Cotton is the second most common fibre in the world, after polyester. In our everyday lives, we are often in contact with something that’s made from cotton (pyjamas in bed, towels after a shower, tea towels when drying the dishes, and whenever you’re wearing T-shirt or jeans).

When determining the quality of cotton, Dr Georgia McCorkill, a fashion lecturer from RMIT, suggests looking for fabric that is soft and smooth: “Good-quality cotton has longer fibres than a cheaper quality.” Longer fibres create a smooth surface without “loose furry fibres poking out”, she says. Another indicator of quality is the weight and opacity: higher quality materials usually use more fibre, so tend to be heavier and thicker.

Tags saying cotton and 100% recycled on a green garment
When it isn’t blended with polyester, recycled cotton is the best option in terms of sustainability, but it is more difficult to find than organic and conventional cottons. Photograph: Firn/Getty Images/iStock

If sustainability is your number one concern, your focus should be on where and how the cotton was grown. Look for cotton that can be traced back to the farm, and check for environmental certifications.

Caroline Poiner, founder of ethically-minded fashion brand Cloth & Co, says conventionally-grown cotton has a range of negative impacts: reduced biodiversity, high water consumption and damaging chemical fertilisers and pesticides. Instead opt for organic or recycled cotton. Generally, she says, organic cotton is easier to identify (it’s right there on the label), but recycled cotton is a more sustainable alternative, provided it is not blended with polyester.

Her preferred cotton is regenerative but it is not readily available on the market. “Hopefully in the not-too-distant future we will see more regenerative agriculture certifications that support farms and organisations to transition to holistic farming techniques that increase soil organic matter, encourage biodiversity and sequester CO2,” she says.


“Wool is often considered one of the most environmentally sound fibres, however there are environmental impacts across the production process from sheep grazing through scouring, spinning, dyeing and finishing,” says McCorkill.

According to Woolmark, 90% of the world’s fine-apparel wool is grown in Australia. Just as with cotton, the environmental benefits and impacts vary greatly between farms depending on the techniques being used, so traceability and certifications are important to understand exactly what impact the wool has had on the landscape, and the sheep.

A close-up of dark blue woolen suit cloth
Look for 100% wool garments that feel soft and do not have short, fluffy fibres on the surface. Photograph: Getty Images/iStock

Poiner suggests supporting brands that advocate for non-mulesed wool and farmers who carry out regenerative farming practices to enhance environmental health, biodiversity, carbon sequestration and water quality. She says: “There are certifications for wool that make it easier to identify these considerations. New Zealand ZQ Merino is relatively new and focuses on the quality, sustainability and ethics of merino wool, from the farm right through to the finished garment.”

When you’re assessing quality, make sure wool knitwear is made from 100% wool and not a synthetic blend. McCorkill says blends pill more, especially if they are predominantly acrylic.

Another indicator of quality is the fibre length and thickness – high-quality wool is made from extremely fine fleeces. “If the wool feels soft and doesn’t have too many short fluffy fibres on the surface, this is a good indication of the longevity of the garment,” says Poiner.

Linen and hemp

Linen and hemp are both bast fibres, meaning the silky strands come from inside the woody stalk of their respective plants. Linen and hemp’s farming processes are the gentlest on the landscape of all the natural fibres, even when grown with conventional methods.

“Linen [flax] and hemp are both considered eco-friendly and sustainable fibres at ground level,” says Poiner. While it’s still preferable to buy certified organic hemp and linen, she says they require fewer (if any) pesticides and fertilisers, and have lower water requirements because they are essentially rain-fed.

Wavy folds of textile made of cannabis and green leaves
Hemp and linen that is rough, scratchy or has uneven slubs (nubbly bits) is generally considered lower quality. Photograph: Yulia Naumenko/Getty Images

Although hemp makes up a tiny fraction of the global fibre market, Poiner says it is an extraordinary fibre. While growing, hemp captures an extraordinary amount of carbon. “According to the European Industrial Hemp Association, it is actually carbon negative,” she says. It also has a deep tap root that draws toxins out of the soil, making it highly effective at improving soil health.

When you’re assessing the quality of linen and hemp, as with cotton, it comes down to the length and strength of the fibres. “If the fabric is scratchy or rough to touch or has uneven slubs [nubbly bits] in the texture, it is likely to be made from shorter fibres and is generally considered … lesser quality.”

That being said, some textiles are deliberately woven for “slubbiness”, which gives a garment a rougher, hairier or slightly bobbly texture.


Sericulture, the practice of raising silkworms and harvesting cocoons for the yarn to make silk, has existed for centuries. “Silk production is relatively low impact and can provide good sources of income alongside other industries,” says McCorkill.

Even so, Poiner suggests looking for silk that’s certified organic or Oeko-Tex certified, which means the mulberry tree farming and silk processing are free from chemicals.

Cocoon silk cloth with colourful designs
Wild silk from Assam in India is generally thought to be more sustainable than conventional silk, but has a different texture due to the shorter fibre length. Photograph: David Talukdar/Getty Images

In traditional silk making, the cocoons are boiled, killing the worm to stop it from breaking out of the cocoon and shortening the fibre. So “from a vegan or animal cruelty perspective, killing each silk moth in its cocoon to preserve the integrity of the long filament that gives silk its lustre is problematic”, says McCorkill.

One alternative is wild or peace silk, where the moths are allowed to break out. “Wild silk and eri silk from Assam is a more sustainable option for both the environment and also Indigenous communities who have relied on the income from the production of silk for generations,” says Poiner. “However, it has a very different quality,” she says, because the fibre is shorter than conventional, single filament silk, which is usually prized for being smooth and, well, silky.


Lucianne Tonti

The GuardianTramp

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