The Ultimate Guide To Underwear Fabrics
When it comes to choosing underwear and lingerie, most people focus on style, fit, and colour. But what’s next to your skin all day long deserves more attention - particularly the fabric it's made from.
Understanding the origins, properties, and environmental and social footprints of the fibres that make up these fabrics can help you make better choices for your comfort, your wardrobe, the planet, and society, and this guide is here to help you do just that.
But before we get started, let’s clear up some terminology.
Fabrics vs. Fibres
Fibres are the raw materials used to create yarns, which are then knitted or woven into fabrics, meaning that in the simplest of terms, fibres create fabrics.
Cotton, for example, is a fibre that is used to create fabrics of various different kinds, like jersey (commonly referred to as 'cotton jersey'). But jersey fabric can also be made out of various other fibres, like bamboo or wool. Similarly, polyester is a synthetic fibre that can be used to make, for example, mesh, satin, or microfibre fabrics, depending on how the fibres are spun and then knitted or woven.
In practice, most underwear and lingerie fabrics are made from a blend of two or more fibres to combine different aesthetic and technical characteristics. An example would be a cotton-elastane blend jersey fabric, leveraging the softness of the cotton fibres and the stretch of elastane.
So although the name of the fabric - jersey, mesh, satin, etc. - is going to give us an idea of its aesthetic and functional properties, it isn't necessarily going to reveal much about its origins or environmental footprint. For that, we need to get to the fibres the fabric is composed of.
And it's for that reason that our guide focuses in on fibres. In the first two sections, we'll look at each fibre used in the production of underwear and lingerie fabrics in turn, explaining for each one: its source, how it's used, its basic attributes, and its environmental and social impacts, awarding it an overall sustainability score.
Jump to:
Natural Fibres
- Cotton
- Organic Cotton
- Viscose (aka Rayon)
- Lyocell and Modal (including TENCEL™)
- Closed-Loop Bamboo (aka Bamboo Lyocell)
- Hemp
- Silk
Synthetic Fibres
- Polyester
- Nylon (Polyamide)
- Elastane / Spandex (aka Lycra)
- Recycled Polyester (rPET)
- Recycled Nylon (e.g. ECONYL)
- Tackling Microfibre Pollution
Reclaimed Fabrics
Conclusion
Section 1: Natural Fibres
These are fibres derived from natural sources - plants and animals.
Natural fibres can be broadly split into two categories: non-synthetic fibres, which can be considered to come (more or less) directly from nature; and semi-synthetic fibres, which ultimately derive from nature, but tend to be more heavily processed, usually by using chemicals to break down the cellulose structure of their respective raw materials.
Natural fibres are often prized for their comfort and breathability, and tend to be considered inherently more environmentally-friendly than synthetic fabrics. In reality, however, their sustainability varies very widely, depending on how the raw materials are cultivated and processed.
1. Cotton
Origin:
Grown from the cotton plant, a crop widely cultivated around the world. The largest producers include India, China, the United States and Brazil.
Commonly fabrics:
Jersey, rib knit, and interlock knit.
Attributes:
Cotton is soft, breathable, and has strong moisture absorption properties. Although raw cotton is naturally hypoallergenic, the processing non-organic cotton undergoes can introduce chemicals that may cause allergic reactions (so those with sensitive skin should look for a certification like the OEKO-TEX STANDARD 100).
Cotton is widely used in underwear for its comfort, durability, and affordability, but can tend to shrink over time and can lose shape without blended fibres.
Sustainability pros:
Cotton is a natural and renewable fibre that is biodegradable in its pure form. It supports many agricultural communities around the world, providing livelihoods in both developing and developed nations.
Sustainability cons:
Conventional cotton farming uses large quantities of synthetic pesticides, herbicides, and fertilisers, contributing to water pollution, soil degradation, and biodiversity loss. Cotton also requires an exceptional amount of water to grow, which is a key concern as climate change drives the increase of arid conditions in large parts of the developing world.
Cotton supply chains are also long and complex. Cotton is often grown in one region, processed into yarn in another, woven and dyed in a third, and manufactured in a fourth, before being shipped for retail in yet another. This multi-stage process, spanning thousands of kilometers, contributes substantially to cotton fabrics' overall carbon footprints.
Human rights issues persist in some regions, with labour exploitation, child labour, and unsafe working conditions still widely reported in parts of the cotton supply chain.
Sustainability Rating: D
2. Organic Cotton
Origin:
Organic cotton derives from the same plant as conventional cotton, but is grown without the use of synthetic chemicals.
Common fabrics:
Jersey, rib knit, and interlock knit.
Attributes:
Organic cotton offers the same basic qualities as regular cotton, and can be more suitable for people with sensitive skin or allergies (although it won't necessarily be, and it's still best to look for toxic-free certifications). Fabrics made from organic cotton are typically more durable than their conventional counterparts when cared for properly.
Organic cotton is commonly used in everyday underwear and basics, providing comfort with a lighter environmental footprint (and usually a significantly higher price tag).
Sustainability pros:
Organic cotton farming avoids synthetic pesticides and fertilisers, improving soil health, reducing water pollution, and offering a lower threat to the surrounding ecosystem. It typically uses less water overall, especially when rain-fed.
The cultivation of organic cotton also promotes safer working conditions by reducing chemical exposure for farmers and workers.
Sustainability cons:
Despite its lower chemical footprint, organic cotton can still be resource-intensive compared other natural fibres. It often yields much less per acre than conventional cotton, requiring more land for the same output. Much organic cotton farming still also requires relatively high amounts of water.
Certification and traceability remain inconsistent globally, making it challenging to verify organic claims in some supply chains.
Sustainability Rating: B (if GOTS/OCS certified) / C
3. Viscose (aka Rayon)
Origin:
Viscose is a form of rayon, a semi-synthetic fibre made from wood pulp - often from bamboo, beech, pine, or eucalyptus. Its production involves dissolving wood pulp in strong solvents to extract cellulose, the main component of plant cell walls, which is then chemically regenerated into fibres.
Common fabrics:
Smooth jersey, satin, lace blends.
Attributes:
Viscose is known for its soft, smooth texture and silk-like drape. It is breathable, moisture-absorbent, and can be used to create fabrics with a satin sheen, which makes it a popular option for fashion underwear and lightweight layering pieces.
Viscose tends to be less durable than other plant-based fibres and can shrink or lose shape if not blended with synthetics or handled with care.
Sustainability pros:
VIscose can be (although often isn't) made from renewable plant sources, is biodegradable in its pure form, and can be a lower-impact alternative to petroleum-based synthetics when responsibly produced.
Sustainability cons:
Most viscose is produced through a polluting process involving carbon disulfide and other toxic solvents. When these solvents aren't treated with care (i.e. in carefully controlled processes, before being recycled or captured and re-processed) they can pose a grave risk to ecosystems and pose severe health risks for workers. Additionally, viscose production has been linked to deforestation of ancient forests and lack of labour protections in some producing countries.
Sustainability Rating: D
4. Lyocell and Modal (including TENCEL™)
Origin:
Lyocell and modal are also types of rayon fibre derived from wood pulp - commonly eucalyptus (lyocell) or beech trees (modal). As with viscose, wood pulp is dissolved in a solvent and then extruded into filaments. But in the case of lyocell and modal, a single non-toxic organic solvent (NMMO) is used, which is then recovered and recycled in a closed-loop process.
Common fabrics:
Smooth jersey, ribbed knits, stretch blends.
Attributes:
Lyocell and modal are known for their luxuriously soft and silky feel. They are highly breathable, wick moisture efficiently, and are naturally smooth against the skin. This makes them ideal for both everyday underwear and more premium, fashion-forward pieces.
The fibres have a satisfying drape, resist wrinkling, and also tend to hold dye well, producing rich, lasting colours.
Sustainability pros:
Lyocell and modal fibres are produced using a closed-loop system that captures and reuses the chemical solvent used to break down the wood pulp, minimising pollution and waste.
The fibres are biodegradable, and the wood they derive from requires less land and water than cotton, and no pesticides or herbicides to grow. Certified versions like TENCEL™ Lyocell ensure responsible forest sourcing.
Sustainability cons:
While the production process is more sustainable than traditional rayon/viscose, it still requires the use of chemical solvents. The sustainability of these fibres depends heavily on responsible forestry and processing practices. In some cases, uncertified modal may come from unsustainable sources.
Sustainability Rating: A (TENCEL™) / B
5. Closed-Loop Bamboo (aka Bamboo Lyocell)
Origin:
Closed-loop bamboo is another form of rayon fibre derived from fast-growing bamboo plants and processed using closed-loop processes (rather than the heavily-polluting viscose method).
Common fabrics:
Jersey, stretch bamboo knits, satin.
Attributes:
Bamboo lyocell is prized for its softness, drapability, and lightweight, silky texture. It has natural antibacterial properties and helps regulate temperature, making it a great choice for both warm and cool climates.
Underwear made from bamboo tends to be breathable, moisture-wicking, and gentle on the skin, suitable for everyday and performance wear.
Sustainability pros:
Bamboo grows extremely quickly without pesticides or herbicides and requires very little water. When processed in a closed-loop system, bamboo fibre production can be environmentally friendly, reducing chemical waste and energy use.
Sustainability cons:
Much of the bamboo marketed as "eco-friendly" is actually bamboo viscose, produced with harsh chemicals in polluting factories. The closed-loop processed versions are significantly better, but certifications and transparency in supply chains are often lacking - look for FSC certification to ensure the bamboo is from a sustainable source, and ECOCERT or OEKO-TEX STeP certification covering closed-loop processing.
Sustainability Rating: B (if suitably certified) / C
6. Hemp
Origin:
Hemp fabric is made from the fibres found in the outer layer of the hemp plant's stalk. The process involves harvesting the stalks, then separating the fibres through a process called retting. After further processing to remove impurities, the fibres are spun into yarn.
Common fabrics:
Lightweight jersey, stretch jersey blends.
Attributes:
Hemp fabric is breathable and naturally textured, though it softens with each wash. It has excellent moisture-wicking and antibacterial properties, and is known for being strong and durable - perfect for underwear that lasts.
While it’s not as silky as lyocell or modal, it has a rustic appeal and blends well with cotton or elastane for improved comfort and stretch.
Sustainability pros:
Hemp is one of the most environmentally friendly fibres. It grows quickly, suppresses weeds naturally, and improves soil health. It requires very little water and no synthetic pesticides or fertilisers. It's also biodegradable and often farmed organically.
Sustainability cons:
Despite its benefits, hemp remains a niche product in the fashion industry. Regulatory issues around hemp cultivation in some countries make it difficult to source, limiting sustainable scaling.
Sustainability Rating: A
7. Silk
Origin:
Harvested from silkworm cocoons, primarily Bombyx mori.
Common fabrics:
Satin, charmeuse, stretch silk blends.
Attributes:
Silk is luxurious, smooth, and naturally temperature-regulating. It feels light and soft against the skin, making it an indulgent choice for lingerie and nightwear.
It’s also strong for its weight and drapes beautifully, though it requires delicate handling and special care (like hand-washing or dry cleaning).
Sustainability pros:
Silk is a natural protein fibre and is biodegradable. It can be produced without chemical fertilisers or synthetic pesticides if done sustainably, and the silk industry often supports artisanal and heritage farming communities.
Sustainability cons:
The traditional silk process involves boiling live silkworms, raising animal welfare concerns. The production is energy- and water-intensive, and cheap mass-market silk may involve exploitative labour. Peace silk (non-violent silk) options exist but are not widely available.
Sustainability Rating: C
Section 2: Synthetic Fibres
Synthetic fibres are man-made, and ultimately derived from petroleum-based chemicals. They are typically made by pushing polymers, which are long chains of repeating chemical units, through a nozzle (called a spinneret) to create long strands.
Synthetic fibres are valued for their durability, elasticity, incredible versatility, and affordability; however, they pose significant environmental challenges.
8. Polyester
Origin:
Polyester is a synthetic fabric primarily made from petroleum-based chemicals, specifically polyethylene terephthalate (PET). It's created through a chemical process known as polymerisation, which results in the formation of long polymer chains which are the basis of polyester fibres.
Common fabrics:
Mesh, satin, microfibre, stretch knits.
Attributes:
Polyester is strong, wrinkle-resistant, and retains its shape exceptionally well, making it ideal for figure-hugging lingerie and shapewear. It also dries quickly, a property valuable in creating activewear and moisture-wicking underwear fabrics. It’s often blended with natural fibres or elastane to enhance comfort and stretch.
Although polyester lacks the breathability of natural fibres, modern blends usually feel surprisingly soft and smooth. Its performance, versatility and affordability see it commonly used in all forms of underwear and lingerie.
Sustainability pros:
Polyester is durable and long-lasting, which can reduce the need for frequent replacements.
Sustainability cons:
Virgin polyester is made from non-renewable petroleum and has a high carbon footprint. The production process involves toxic chemicals and energy- and water-intensive practices. It sheds microplastic microfibres during washing, polluting waterways and marine ecosystems (see the section on Tackling Microfibre Pollution below and our Sustainable Garment Care Guide for tips on how to mitigate against microfibre shedding). End-of-life disposal is problematic since polyester is not biodegradable and is rarely recycled.
Sustainability Rating: E
9. Nylon (Polyamide)
Origin:
Nylon is another synthetic polymer made from monomers derived from petroleum. These monomers, primarily hexamethylenediamine and adipic acid, undergo polymerisation to form long chains of polyamide, which is the core component of nylon.
Common fabrics:
Lace, mesh, microfibre, satin.
Attributes:
Nylon is lightweight, silky, and incredibly strong. It has excellent stretch and recovery, making it ideal for snug-fitting garments like bras, bodysuits, and seamless underwear. It offers a smooth feel against the skin and resists abrasion, contributing to long product life.
Nylon's versatility allows it to mimic the sheen and drape of silk or the structure of technical fabrics, depending on how it's processed.
Sustainability pros:
As with polyester, nylon's durability means garments can last a long time with proper care. It also maintains its shape well, reducing premature disposal due to wear and tear.
Sustainability cons:
Virgin nylon is energy-intensive to produce and generates nitrous oxide, a greenhouse gas with a global warming potential significantly higher than carbon dioxide. Like polyester, it sheds microplastics and is not biodegradable. The production process involves toxic chemicals, and labour conditions in large-scale synthetic textile manufacturing can lack transparency.
Sustainability Rating: E
10. Elastane / Spandex (aka Lycra)
Origin:
Elastane, also known as spandex or lycra, is a synthetic fibre made primarily from polyurethane. The production process involves dissolving polyurethane in a chemical solvent, then dry-spinning it into fibres.
Common fabrics:
Blended with cotton, modal, nylon, or polyester in stretch jerseys, mesh, lace.
Attributes:
Elastane is highly elastic, capable of stretching five to eight times its length, and is primarily used to enhance the fit, flexibility, and shape retention of underwear fabrics. Used in small percentages (usually 2–10%), it transforms static fabrics into body-hugging, movement-friendly materials.
Though rarely used alone, elastane is a key ingredient in many modern underwear fabrics - used in everything from sports bras and shapewear, to everyday knickers - thanks to the comfort and support it provides.
Sustainability pros:
Because it is used in small proportions, its presence allows garments to perform better and last longer, particularly by retaining shape and elasticity, again reducing the likelihood of early disposal due to wear.
Sustainability cons:
Elastane is fully synthetic, non-biodegradable, and as it cannot be recycled in most systems, it complicates the recycling of blended fabrics. Production relies on harmful chemicals, and labour practices are not consistently regulated for worker safety and environmental protection.
Sustainability Rating: D
11. Recycled Polyester (rPET)
Origin:
rPET, or recycled polyethylene terephthalate, is made by collecting, cleaning, and melting down used plastic bottles and other PET packaging. This recycled material can then be used to create various new kinds of products, including fibres for fabrics.
Common fabrics:
Mesh, jersey, satin, blends.
Attributes:
Recycled polyester offers the same strength, durability, and performance as virgin polyester. It feels smooth, holds colour well, and resists shrinking and wrinkling. As a direct substitute for virgin polyester, in underwear, it’s used for its lightweight and quick-drying properties.
Sustainability pros:
By reusing existing plastic, rPET reduces landfill waste and the demand for virgin fossil fuels. It has a much lower carbon footprint than virgin polyester, uses less energy and water in its production, and can extend the life cycle of materials that would otherwise pollute the environment. rPET also supports a growing recycling infrastructure.
Sustainability cons:
Despite being recycled, rPET still sheds microplastics and remains non-biodegradable. The recycling process itself requires energy and chemical treatment. Availability of high-quality feedstock and global recycling standards vary, making traceability and quality assurance inconsistent - look for the Global Recycled Standard (GRS) gold standard certification.
Sustainability Rating: B (if GRS-certified) / C
12. Recycled Nylon (e.g. ECONYL)
Origin:
Recycled nylon is made through a process of recovering and regenerating nylon waste, primarily from items like fishing nets, fabric scraps, and industrial plastics, into a high-quality nylon yarn. The process involves breaking down the cleaned nylon waste into its basic building blocks through a process called depolymerisation (essentially reversing the polymerisation that created the original nylon) before repolymerising to create nylon chips, which can be spun into yarn.
Common fabrics:
Mesh, lace, microfibre blends.
Attributes:
Recycled nylon is identical in performance to virgin nylon - lightweight, smooth, stretchy, and strong. It’s ideal for creating sleek performance underwear and activewear.
Sustainability pros:
Recycled nylon diverts waste from landfills and oceans, including harmful fishing nets. Its closed-loop regeneration systems lower reliance on crude oil and reduce greenhouse gas emissions, whilst supporting efforts to clean marine environments and promote circularity in fashion.
Sustainability cons:
As with recycled polyester, recycled nylon still sheds microplastics, is non-biodegradable, and recycling infrastructure is limited. High costs and technological barriers mean that recycled nylon is not yet widely accessible or affordable.
Sustainability Rating: B
Tacking Microfibre Pollution
All fabrics shed tiny fibres when they're machine washed, whether they're composed of natural or synthetic fibres. These fibres enter washing machine wastewater, and as some are too small to be captured by washing machine or sewage treatment plant filters, they ultimately find their way into rivers and the marine environment.
Thanks to recent high-profile environmental campaigns, most people are now aware of the dangers posed to human and animal health and the wider ecosystem by microplastics, and one form of microplastic is synthetic microfibres.
There are various ways to mitigate the threat of synthetic microfibre pollution, including washing clothes less frequently and on shorter, cooler cycles, and always washing full machine loads, which reduces the friction between articles that causes microfibre shedding. (See our Sustainable Garment Care Guide for more useful tips.)
Another solution is a microfibre-capturing washing bag, like the GUPPYFRIEND, which both reduces the amount of fibres which break away from synthetic clothing and collects those fibres which do break away, so that after washing they can be easily removed and disposed of conscientiously.
Section 3: Reclaimed and Upcycled Fabrics
And now we turn the discussion to fabrics, rather than fibres, because there's one group of fabrics which offers a sustainability free-hit...
Origin:
Reclaimed fabrics are any textiles which have been salvaged from discarded materials and repurposed in order to be made into into new products, diverting them from landfills or incineration. (This contrasts with recycled fabrics, which are made by breaking down old fabrics into fibres and then re-spinning them into new yarn. Reclaimed fabrics are essentially "rescued" and reused in their existing form.)
Reclaimed fabrics can come in the form of factory line-ends (fabric discarded when a garment production run has been completed), off-cuts, or even entire rolls of fabric (known as 'deadstock') which have been ordered and subsequently abandoned by mainstream fashion retailers when production plans or trends have shifted.
Common fabrics:
All types - jersey, mesh, lace, satin, microfibre, and more - depending on the original source of the textile waste.
Attributes:
Reclaimed and upcycled fabrics perform the same as their original fibre counterparts. A cotton jersey made from factory off-cuts will still feel soft and breathable, while a lace made from surplus nylon will retain its delicate structure and stretch. The appeal of upcycled fabrics often lies in their uniqueness - limited edition prints, small-batch production, and one-of-a-kind combinations are common.
Because they avoid the energy-intensive process of creating new fibres, these fabrics retain their original comfort, look, and function with the added benefit of reducing textile waste. They are found in both artisanal and designer collections as well as in circular fashion initiatives.
Sustainability pros:
The primary sustainability advantage of reclaimed and upcycled fabrics is that they avoid the need for new resource extraction. No additional water, land, energy, or chemicals are required to grow, harvest, or process fibres, making this approach inarguably the most environmentally friendly of all.
Not only does the model require no new resources, it also reduces waste, lowers landfill use and incineration, and contributes to a more circular textile economy.
Upcycling often takes place in smaller production environments where artisans or ethical factories can pay closer attention to worker conditions, increasing the likelihood of fair labour practices and transparency in the supply chain.
Sustainability cons:
Where fabrics which include synthetic fibres are used, clothing will still shed microplastics, so the same care should be taken with washing.
Sustainability Rating: A
Conclusion: Choosing The Right Fabrics For Your Body - And The Planet
Underwear is personal, and the fabrics that work best for each of us will depend on our needs, our values, our circumstances, and our budgets.
If you’re all about breathability and comfort, GOTS-certified organic cotton, lyocell and modal, and certified bamboo lyocell are popular choices for more eco-friendly underwear.
Prefer something sleek and sexy or simply more durable? Nylon or polyester blends may appeal, but look for certifiably recycled options for your sustainble lingerie, and make sure you mitigate against microfibre shedding.
Looking for the most eco-conscious options of all? Hunt out garments made from reclaimed fabrics, organic hemp, or certifiably closed-loop processed natural fibres like those bearing the TENCEL™ mark.
Here’s a quick recap of sustainability scores:
| Fibre | Sustainability Grade |
|---|---|
| All Reclaimed Fabrics | A |
| Hemp | A |
| Lyocell/Modal | A (for TENCEL™) / B |
| Organic Cotton | B (if GOTS/OCS-certified) / C |
| Closed-Loop Processed Bamboo | B (if suitably certified) / C |
| Recycled Polyester | B (if GRS-certified) / C |
| Recycled Nylon | B |
| Silk | C |
| Cotton (Non-Organic) | D |
| Viscose | D |
| Elastane/Spandex | D |
| Polyester | E |
| Nylon | E |
By understanding the fibres behind your fabrics, you can make smarter, more sustainable choices.
Whether you’re shopping for luxury lingerie, everyday briefs, athletic underwear, or loungewear, your choice of fabric matters - for your skin, your peace of mind, textile industry workers, and the Earth.
At ColieCo, we've pledged that each and every fabric that we'll ever use in the production of your lingerie and underwear meets strict sustainability criteria. You can learn about all of the fabrics we're currently using here.
