We see the same buzzwordy materials pop up time and time again in slow fashion spaces — organic cotton, reclaimed fabric, linen, TENCEL™. But what do these phrases really mean when it comes to truly sustainable and nontoxic clothing? Today’s conscious consumers are looking beyond just “natural” labels, paying closer attention to hidden chemical finishes like PFAS (so-called “forever chemicals”) often used for stain or water resistance, as well as the potential for microplastic shedding in certain synthetics. We also want clothes that are durable and designed to last — because no matter how “eco” a fabric claims to be, fast-wearing pieces that end up in the landfill after a season aren’t truly sustainable.

So, is all clothing made with these trendy materials automatically eco-friendly, skin-safe, and long-lasting? And which fabrics actually check all the boxes for sustainability, chemical safety, and everyday wearability? The answer is more nuanced than you might expect. We break it all down below with the help of a sustainable fashion expert.

Glossary of fabrics:

Why do sustainable & natural fabrics matter?

The fast fashion industry, which is the second-largest polluter of water and the third-largest polluter overall, thrives on producing quick, cheap virgin materials, like polyester, spandex, viscose, and nylon. Used to make low-quality clothing, textiles like these make up 8% of municipal waste, and take decades or more to biodegrade, releasing microplastics into the environment during the process.

“How do we tell if a garment is made from a truly sustainable natural fiber fabric?”

So, what fabrics should we look for when purchasing new clothing? Lottie Bertello, founder and design director of LOTI, an upcycling design studio based between Peru and LA, says that upcycled products are king “in terms of resource use and waste reduction.” 

And, as a “very general” rule of thumb, she says to stick to natural fibers like organic cotton, linen, hemp, silk, wool, alpaca, and bamboo. “I’ve run into so many TikToks of people getting horrible skin rashes after wearing a Shein garment, and it’s like, of course,” she laughs, “you’re wearing a poorly developed textile made mostly from crude oil.”

But how do we tell whether a garment is made from a truly sustainable natural-fiber fabric? More on that below.

What makes fabric sustainable?

“Not all natural fibers are created equally,” says Bertello, “and I personally do not consider a fabric sustainable unless it’s ethically made.” Sure, a garment might be handmade in a California studio from hemp — but is the brand telling you that hemp was woven ethically? That’s the marker of a truly sustainable fabric.

“Alpaca is hands down the most sustainable animal fiber out there.”

Lottie Bertello, founder and design director of LOTI

While Bertello loves upcycled fabrics, she also notes that new technologies have helped reduce the energy and water required to make fabrics like organic cotton and denim. She also touts the benefits of alpaca, calling it a “highly underrated” textile. “Alpaca is hands down the most sustainable animal fiber out there,” she says, likening it to cashmere in terms of fiber quality, softness, durability, and price. “Alpacas graze in a way that’s gentler on the environment,” she notes, “one alpaca’s wool can provide enough material to make four or five sweaters,” and the material is super economically beneficial to Andean communities. 

Bertello’s least favorite fabric? Polyester, and anything made of polyester, like fleece, spandex, and viscose. “I’ll admit, I break this rule for ‘performance’ garments like swimwear and sportswear,” she notes, but it’s getting easier to find more sustainable activewear made of cotton with a touch of spandex.

How to shop for sustainable & natural fabrics:

A truly ethical brand will make it clear through its platforms that they’re working to use the most environmentally friendly versions of its materials. When in doubt, ask! Most brands that call themselves ethical will be more than happy to respond to an email or DM asking how they source their fabrics to ensure they are ethically produced. “I love getting messages like this because it tells me the gal who shops at LOTI is curious and cares,” says Bertello.

As always, even with sustainable fabrics, the less you buy, the more sustainable you’ll be. You’re much better off buying a piece you’ll rewear for years and years than several ethically sourced, sustainably made garments you’ll donate after a year or care for improperly.

“Sustainability is not a product or something that can be bought.”

Lottie Bertello

Websites like Good On You are excellent resources to learn more about a brand’s practices. And keep in mind that there’s no one perfect, sustainable fabric that’ll have zero environmental impact. The idea is that the list below will help you become a more informed consumer and make more conscious, ethical decisions when shopping for clothes.

“Sustainability is not a product or something that can be bought,” says Bertello. “It’s a holistic shift to living in harmony with our environment, which means not taking more than we need.” Read on for the lowdown on a handful of the most environmentally sustainable fabrics.

The best sustainable & natural fabrics:

Alpaca

Pros: Alpaca wool is water-resistant and temperature-regulating. It takes little to no chemicals to produce, and Alpacas graze in a way that’s less damaging to the environment than sheep. Alpaca wool is biodegradable and often more durable than sheep’s wool. 

Cons: Alpaca can be pricey, so make sure to look for certified organic and fair-trade labels.

Brands we love for Alpaca wool: Mamacha, Christy Dawn

A woman stands outdoors wearing a gray sweater with red stripes and pink striped shorts, holding a red bag. The background features a street with buildings and parked cars.
Person sitting on carpeted stairs wearing a red dress, gray leg warmers, and brown clogs, with hands resting beside them.
(L) Christy Dawn; (R) Mamacha

Bamboo

Pros: Bamboo is a fast-growing, regenerative crop that requires little or no fertilizer or pesticides. The process to mechanically turn it into bamboo linen requires little or no chemicals.

Cons: It’s almost impossible to know if the bamboo you’re buying was farmed sustainably. And when bamboo is turned into soft garments like sheets, socks, and pajamas, it must undergo an intensive chemical process, the same way viscose (or rayon) is made; however, in recent years, manufacturers have improved chemical management. 

Brands we love for bamboo: Boody, Cozy Earth

A person stands wearing a sleeveless black maxi dress with spaghetti straps and black sandals against a plain light background.
A woman stands wearing light green striped short-sleeve pajamas with matching shorts and beige slippers, against a plain light background.
(L) Boody; (R) Cozy Earth

ECONYL®

Pros: ECONYL® is made of regenerated nylon waste, making it a popular alternative to virgin nylon. It’s upcycled from fishing nets and waste fabrics, using much less water and energy than producing nylon from scratch.

Cons: It’s still made of nylon, so it can shed microplastics in the wash — consider using a garment bag or washing as infrequently as possible.

Brands we love for ECONYL®: Reformation, Galamaar

A woman sits on the floor wearing a white sweater, white lace tights, and black flats, with one hand covering her mouth and her legs crossed.
A woman wearing a rust-colored one-piece swimsuit stands outside against a white wall with arches, surrounded by trees and greenery.
(L) Reformation; (R) Galamaar

Linen

Pros: Linen is made of flax, a fast-growing plant that traps carbon and doesn’t require fertilizer, pesticides, or much water. Almost the entire flax plant can be woven into linen clothing, so there’s almost no waste left over — and linen is biodegradable and strong.

Cons: You’ll want to read the label to find out if your linen was produced organically. Linen fibers have virtually no stretch, so they wrinkle easily, and linen can be expensive since almost all of it is produced ethically in Europe.

Brands we love for linen: MagicLinen, Linenfox, Love and Confuse

Woman with curly hair wearing a white button-up shirt and green pants stands outdoors in front of greenery.
Person standing outdoors in a field of yellow flowers, wearing a light yellow checkered shirt, loose white pants, and black shoes.
(L) MagicLinen; (R) Linenfox

Modal

Pros: A semi-synthetic material, modal is made from a chemical process using the wood of beech trees, which use much less water to grow than crops like cotton. Modal is stretchy and absorbent, making it a good activewear alternative. TENCEL™ modal clothing, specifically, is made from sustainably farmed trees and uses a more energy-efficient, less toxic chemical process.

Cons: Like viscose, modal is at least partly synthetic, and some modal is made with harmful chemical processes and untraceable wood.

Brands we love for modal: tentree, LA RELAXED

A woman stands outdoors on rocky ground, wearing a yellow knit sweater, a blue patterned skirt, and sneakers, with dry shrubs and a hill in the background.
A woman with wavy, light brown hair stands in front of a wooden wall, wearing a brown V-neck sweater over a white shirt and looking calmly at the camera.
(L) tentree; (R) LA RELAXED

Organic Cotton

Pros: Soft, stretchy, and breathable, organic cotton is grown with no toxic pesticides, synthetic fertilizers, or genetically modified seeds (GMOs). Look for a GOTS or OCS certification when shopping for organic cotton clothing.

Cons: Cotton takes a lot of water to farm, although organic cotton usually uses less than conventional cotton. 

Brands we love for organic cotton: Pact, MATE the Label, Harvest & Mill

A woman stands against a plain background wearing a taupe sports bra and matching high-waisted leggings.
A person with pulled-back hair, wearing a beige t-shirt and drawstring pants, stands outdoors with trees and sunlight in the background.
(L) MATE the Label; (R) Harvest & Mill

Organic Hemp

Pros: Hemp requires little resources to grow and to spin into threads and fabrics, making it fairly sustainable when grown organically. It’s one of the oldest used textiles, and it has a similar feel to linen — durable and breathable. 

Cons: Like bamboo, some hemp is produced through the viscose method, which uses lots of chemicals. In this case, it’ll usually be labeled “hemp viscose.” And because of its association with marijuana (it won’t get you high!), it typically requires a special license to grow. 

Brands we love for hemp: Jungmaven, Patagonia

A person with long curly hair wearing a navy tank top and white shorts stands against a plain background.
A woman stands facing forward wearing a sleeveless, teal jumpsuit with wide legs and sandals against a plain light background.
(L) Jungmaven; (R) Patagonia

Piñatex

Pros: Piñatex is a leather alternative — and while leather is natural material that lasts for a long time, it’s a byproduct of an industry that’s currently highly unsustainable: Cattle ranching. Many vegan leathers are made of plastic, but not Piñatex — it’s made of leftover pineapple leaves that would otherwise be burned.

Cons: It’s not quite as durable as leather, and it won’t fully biodegrade on its own.

Brands we love for Piñatex: NAE

Two people standing side by side wearing light-colored clothing and black sandals, with only their legs and feet visible against a plain background.
A person wearing a white sneaker and a white ribbed sock with the word "nae" printed on it, standing against a beige background.
NAE

Reclaimed (Deadstock)

Pros: Reclaimed, deadstock, or upcycled fabrics are some of the most sustainable fabrics available since they take less energy and resources to make than virgin fabrics.

Cons: Some reclaimed fabrics come from polyester, which still releases microplastics when it’s washed. 

Brands we love for deadstock: Lisa Says Gah, Whimsy + Row

A person stands on a beach wearing a white tank top with a shell design and an olive green textured skirt with decorative buttons at the waist.
A woman stands indoors wearing a black pinstripe vest and skirt over a white turtleneck top, holding a red jacket in her hand. Wooden vertical panels form the background.
(L) Lisa Says Gah; (R) Whimsy + Row

RPET

Pros: RPET is recycled polyethylene terephthalate, and it uses about 80% less energy to make than virgin polyester. It has almost identical characteristics to polyester, so it’s great for activewear, and it’s made of recycled plastics like water bottles.

Cons: It’s made of plastics, so it can release microplastics when it’s washed — and it can’t be further recycled. 

Brands we love for RPET: Girlfriend Collective

Person wearing a grey sports bra and leggings with white socks and grey sneakers, standing and stretching one arm across their chest against a plain background.
A woman stands against a plain background wearing a sleeveless, cream-colored dress with a cross halter neckline and small front slits.
Girlfriend Collective

Silk

Pros: Silkworms eat only the leaves of mulberry trees to produce their silk, and spinning the fibers into silk fabric is a fairly low-waste production.

Cons: Because silk comes from caterpillars, it’s not vegan. Some types of silk, like ahimsa silk, are touted as cruelty-free, but evidence of actual cruelty-free silk is limited.

Brands we love for silk: Quince, Sézane

A person stands against a plain background wearing a black camisole top, an olive green satin midi skirt, and black sandals.
A person with short blonde hair sits on a red-brown couch, wearing a leopard-print shirt and brown pants, looking at the camera.
(L) Quince; (R) Sézane

TENCEL™ Lyocell

Pros: Similar to TENCEL™’s modal, their lyocell is made of eucalyptus wood that goes through the viscose process but in a closed loop, so chemicals are reused over and over. Their eucalyptus is sourced sustainably. TENCEL™’s lyocell is stretchy and easy to wear, and it’s certified biodegradable.

Cons: They still use a chemical process, making the clothes semi-synthetic.

Brands we love for TENCEL™ Lyocell: Everlane, Organic Basics

Woman standing against a plain background, wearing a light blue buttoned long-sleeve top, navy high-waisted shorts, and black sandals. Hands in pockets, facing forward.
A woman stands against a plain background wearing a matching light mauve bra and underwear set, with her arms raised above her head.
(L) Everlane; (R) Organic Basics

Wool

Pros: Made by sheep, wool is completely natural, biodegradable, and renewable. It’s a temperature regulator, meaning it keeps you warm in the winter and cool in the summer. Wool is durable, and its production doesn’t have to harm the sheep involved.

Cons: Wool isn’t vegan, and unfortunately, not all sheep farming is alike. Look for certifications that ensure the animals were treated fairly, like the Responsible Wool Standard or the ZQ certification.

Brands we love for wool: NAADAM, EILEEN FISHER

A person wearing a light gray sweater and white pants with a brown belt stands against a plain background, resting one hand on the back of their neck.
A woman stands against a plain background wearing a light knitted short-sleeve top, wide-leg beige pants, and beige lace-up shoes.
(L) NAADAM; (R) EILEEN FISHER

Cork

Pros: Harvested from the bark of cork oak trees without harming them, cork is a renewable, biodegradable, and surprisingly durable material often used in accessories.

Cons: Cork can be more expensive and may develop small cracks over time with heavy use.

Brands we love for cork: Birkenstock

Two people standing side by side, both wearing sandals; one in a yellow shirt and brown pants, the other in a black shirt and light pants against a plain background.
A person wearing a light beige skirt and gray double-strap sandals with gold buckles, standing against a plain white background.
Birkenstock

Cactus Leather

Pros: Cactus leather is an eco-friendly, vegan alternative to animal leather that’s partially biodegradable and requires very little water to produce.

Cons: It’s not as widely available yet and can be less durable than traditional leather in heavy-use or high-stress applications.

Natalie Gale is a Boston-based freelance journalist. When she’s not writing about art, food, or sustainability, you can find her biking to the farmers’ market, baking, sewing, or planning her next Halloween costume. Say hi on Instagram!