Most clothing is made from either natural fibers like cotton and wool, synthetic fibers like polyester and nylon, or blends of both. Polyester is the single most common material in the world’s clothing supply, making up 59% of all fiber produced globally. Cotton comes in second at 19%. The rest is a mix of other synthetics, plant-based fibers, wool, silk, and newer semi-synthetic materials made from wood pulp.
Natural Fibers: Cotton, Wool, and Silk
Natural fibers come from plants or animals and have been used for thousands of years. Cotton, the most common natural fiber, is almost pure cellulose, the same structural molecule that gives plants their rigidity. Each cotton fiber is a tiny tube between 1 and 6 centimeters long, harvested from the seed pod of the cotton plant. Cotton absorbs moisture well, with a moisture regain of 7 to 11%, which is why cotton t-shirts feel comfortable against skin but take a while to dry.
Wool comes from sheep (and similar animals like goats, alpacas, and rabbits) and is made primarily of keratin, the same protein in your hair and fingernails. Wool’s big advantage is its ability to absorb up to 17% of its weight in moisture before it feels damp, which helps regulate body temperature in both cold and warm conditions. Silk is also a protein fiber, produced by silkworms as two strands of a protein called fibroin glued together with a natural gum that accounts for 10 to 20% of raw silk’s weight. That gum gets washed away during processing, leaving the smooth, lustrous threads you see in finished silk fabric.
Flax, the plant behind linen fabric, is another cellulose fiber. It’s stronger than cotton and dries faster, which is why linen is a warm-weather staple. Hemp and jute round out the common plant-based fibers, though they show up less often in everyday clothing.
Synthetic Fibers: Polyester, Nylon, and Acrylic
Synthetic fibers are manufactured from petroleum-derived chemicals. Polyester, the world’s dominant fiber, is technically polyethylene terephthalate (PET), the same polymer used in plastic water bottles. It’s made by combining two petroleum-based chemicals and spinning the resulting plastic into fine threads. Polyester is cheap to produce, holds its shape well, dries quickly, and resists wrinkles. Its moisture regain is just 0.4%, which means it barely absorbs water. That’s great for quick-drying athletic wear but can feel clammy against skin.
Nylon was the first fully synthetic fiber, originally derived from coal and petroleum. It’s exceptionally strong for its weight and stretches more than polyester, making it common in activewear, hosiery, and outerwear. Acrylic fiber mimics the look and warmth of wool at a lower cost and absorbs almost no moisture (1 to 2% regain). You’ll find it in sweaters, blankets, and cold-weather accessories.
Spandex (also sold under the brand name Lycra) is a synthetic fiber built for extreme stretch. It can elongate to several times its resting length and snap back. You rarely see 100% spandex garments. Instead, a small percentage is blended into other fabrics to add flexibility.
Semi-Synthetic Fibers: Rayon, Viscose, and Lyocell
Semi-synthetic fibers sit between natural and synthetic. They start as natural plant material, usually wood pulp from trees or bamboo, but require heavy chemical processing to dissolve that pulp and re-form it into usable threads. Viscose rayon is the most common type and has a moisture regain of about 13%, which gives it a soft, breathable feel similar to cotton. Lyocell (often sold as Tencel) uses a less toxic solvent in its production and is generally considered more environmentally friendly than traditional viscose.
Life cycle assessments show that the raw material matters. Bamboo-based viscose tends to carry a lighter environmental footprint than wood-based viscose, which in turn performs better than viscose made from cotton pulp. But all versions require significant energy and chemical inputs during manufacturing.
Why Most Clothing Is a Blend
Check the label on almost any garment and you’ll likely see two or more fibers listed. Blending fibers lets manufacturers combine the comfort of one material with the durability or stretch of another. A typical 65/35 cotton-polyester blend still feels like cotton but shrinks less, wrinkles less, dries faster, and lasts longer. Adding just 20% polyester to cotton noticeably improves abrasion resistance and seam strength, and bumping that up to 35% produces a disproportionate jump in durability.
Spandex blends follow a different logic. Even 1 to 2% spandex gives a fabric gentle give, while 3 to 5%, the most common range in everyday clothing, provides noticeable stretch with strong recovery. Jeans, chinos, and dress shirts increasingly include this small percentage so they move with your body and hold their shape after repeated wear. At 6 to 8%, you’re in the territory of yoga pants and compression wear. Above 10%, the fabric is built for high-performance athletics.
Nylon blends work similarly: 5 to 20% nylon added to cotton significantly increases tensile strength and abrasion resistance without sacrificing much comfort.
Chemical Finishes on Fabric
The fiber itself is only part of what you’re wearing. Most clothing goes through finishing processes that add specific properties. Wrinkle-resistant dress shirts, for example, have traditionally been treated with formaldehyde-based resins that create chemical bridges between cellulose fibers, physically preventing them from creasing. Water-resistant jackets and stain-repellent pants have often relied on fluorine-containing coatings to create a surface that repels liquids. These coatings contain PFAS, sometimes called “forever chemicals,” which persist in the environment and have been linked to health concerns. Many manufacturers are now phasing them out.
Researchers are developing plant-based alternatives. One promising approach uses epoxidized cottonseed oil to bond with cellulose fibers, creating both wrinkle resistance and water repellency without formaldehyde or PFAS. These bio-based finishes are still emerging but reflect a broader industry shift toward safer chemistry.
Microfiber Shedding From Synthetics
Every time you wash synthetic clothing, tiny plastic fibers break loose and flow into wastewater. Research published in Scientific Reports found that a single wash cycle releases between 640,000 and 1.5 million microfibers, depending on the garment type. That translates to roughly 124 to 308 milligrams of microplastic per kilogram of fabric. Knitted polyester garments made with continuous filament yarns shed more consistently, while woven fabrics tend to release less. These microfibers are too small for most wastewater treatment plants to fully capture, and they eventually reach rivers and oceans.
If this concerns you, washing synthetic clothes less frequently, using a cooler water temperature, and placing garments in a microfiber-catching wash bag can reduce shedding.
Mushroom Leather and Bio-Based Materials
A newer category of clothing materials comes from biology rather than farming or petroleum. Mycelium, the root-like network of fungi, is being grown into sheets that resemble leather. Companies like MycoWorks cultivate a genus of fungi called Ganoderma on trays of organic material. The fungus digests the biomass and grows a dense, interlocking mesh of filaments called hyphae. The result is a material that is simultaneously soft, dense, and strong. In some cases, fabric is placed in the growing tray as scaffolding, and the mycelium weaves through it to create a composite material.
Other producers use bioreactor tanks, similar to brewery fermentation systems, to grow mycelium in liquid culture. The slurry is strained out and poured onto molds to dry into any desired shape. These materials are still niche and expensive, but they represent a genuinely different approach to making clothing, one that grows rather than extracts its raw material. Recycled fibers, meanwhile, account for about 7.6% of global fiber production, with recycled polyester making up the largest share at 12% of all polyester output.