Cloth is made from fibers, either natural (from plants and animals), synthetic (from petroleum-based chemicals), or semi-synthetic (natural materials processed with chemicals). These fibers are spun into yarn and then woven, knitted, or bonded together to form fabric. Polyester, a synthetic fiber, is the most produced globally at 57% of all fiber production, followed by cotton, the leading natural fiber at roughly 24 million tonnes per year.
Plant Fibers
Cotton is the most familiar plant fiber. It comes from the fluffy bolls that surround the seeds of the cotton plant, and its softness and breathability have made it a textile staple for thousands of years. Cotton fibers are almost pure cellulose, the structural carbohydrate that gives plants their rigidity.
Linen comes from the stems of the flax plant. It belongs to a category called “bast fibers,” meaning the usable material sits inside the plant’s stalk and has to be separated out through a process called retting (essentially controlled rotting). Hemp is another bast fiber. It grows quickly, resists many insect species naturally, and often needs little water compared to cotton. Jute, the fiber used in burlap sacks, is also a bast fiber, harvested from plants grown mainly in South Asia.
Less common plant sources include kapok (a silky fiber from tropical seed pods) and kenaf (a relative of hibiscus). In recent years, fibers from pineapple leaves, banana leaves, and even orange and olive waste have been developed into experimental textiles, particularly in Egypt and Morocco.
Animal Fibers
Wool and silk are the two major animal fibers, and they’re built from very different proteins. Wool is made of keratin, the same protein found in human hair and fingernails. Cells in a sheep’s skin follicles rapidly produce keratin, which hardens into the crimped, springy fibers that get sheared off as fleece. Sheep aren’t the only source: cashmere comes from cashmere goats, mohair from Angora goats, and other keratin-based fibers come from alpacas, yaks, camels, and even elk.
Silk works completely differently. Silkworms (the larvae of a specific moth species) produce a liquid protein called fibroin, which hardens into a continuous filament as they spin their cocoons. A single cocoon can yield hundreds of meters of usable thread. This is why silk has that distinctive smoothness: unlike wool’s short, scaly fibers, silk is one long, unbroken strand with a naturally glossy surface.
Synthetic Fibers
Most cloth produced today is synthetic, made from polymers derived from petroleum. Polyester alone accounts for 57% of global fiber production. Its full chemical name is polyethylene terephthalate (PET), and it’s built from two petroleum products: ethylene glycol and terephthalic acid. These are bonded together into long chains, melted, and forced through tiny holes to create filaments. The result is a fiber that’s strong, wrinkle-resistant, and cheap to produce.
Nylon was the first truly synthetic fabric, developed in the 1930s. It’s a polyamide, meaning its molecular chain is held together by the same type of chemical bond found in proteins. Nylon is elastic and exceptionally strong for its weight, which is why it shows up in everything from stockings to parachutes. Acrylic fibers round out the big three synthetics. They’re made from a compound called acrylonitrile and are designed to mimic the warmth and softness of wool at a lower cost.
Semi-Synthetic Fibers
Some fibers sit between natural and synthetic. Rayon, viscose, and lyocell all start as wood pulp (cellulose from trees like eucalyptus or beech), but require heavy chemical processing to become fiber. The wood pulp is dissolved into a liquid, then extruded through tiny nozzles to form threads that re-solidify.
The key difference among them is how that dissolving happens. Traditional viscose production uses harsh chemicals that generate significant air and water pollution. Lyocell (sold under the brand name Tencel) uses a non-toxic organic solvent that can be recovered and reused in a closed loop, making it considerably cleaner. Both produce soft, breathable fabrics that drape well, which is why they’re popular in clothing. Together, these “man-made cellulosic fibers” represent about 6% of global fiber production, with output growing from 7.4 million tonnes in 2022 to 7.9 million in 2023.
How Fibers Become Fabric
Raw fibers don’t become cloth on their own. They need to be constructed into a flat, stable material, and there are three main ways to do it.
Weaving interlaces two sets of yarns at right angles: one running lengthwise (the warp) and one running crosswise (the weft). The pattern of interlacing determines the fabric’s texture and strength. A plain weave alternates over-under in the simplest pattern possible. Twill weaves create diagonal ridges (think denim). Satin weaves produce a smooth, glossy surface by letting long stretches of yarn float over multiple cross-threads before tucking under.
Knitting loops a single yarn through itself repeatedly, creating a stretchy, flexible fabric. Your t-shirt is almost certainly knitted. Knit fabrics stretch and recover in ways woven fabrics can’t, which is why they dominate casual and athletic wear.
Nonwoven fabrics skip yarn entirely. Loose fibers are bonded together directly using heat, chemicals, or mechanical pressure. Felt is a traditional example. Modern nonwovens include surgical masks, disposable wipes, and some insulation materials.
What Gets Added After Construction
Finished cloth is rarely just fiber. Textile manufacturing involves a long chain of chemical treatments: bleaching agents like hydrogen peroxide to whiten fabric, acids for pH control, salts to help dyes bond with fibers, and fixing agents to keep colors from washing out. Optical brighteners make whites appear whiter under light. Scouring agents strip natural oils and waxes from raw fibers before dyeing can begin.
Beyond color, fabrics can receive coatings for water resistance, wrinkle resistance, flame retardancy, or antimicrobial properties. These chemical finishes are part of what gives a finished garment its specific performance characteristics, and some remain in the fabric through its entire usable life.
Environmental Tradeoffs
The dominance of synthetic fibers carries a specific environmental cost: microplastic shedding. Every time you wash a polyester garment, it releases hundreds of thousands of tiny plastic particles into the water. These microplastics have been detected in rivers, lakes, oceans, and even remote Antarctic waters. They accumulate in fish, shrimp, crabs, and other aquatic organisms. Knitted polyester fabrics shed more microplastics than woven ones, and among woven types, satin weaves release the most while plain weaves release the least.
Natural fibers biodegrade but come with their own costs. Cotton is water-intensive and often pesticide-heavy. Wool production requires grazing land and generates methane. This tension has driven interest in newer bio-based materials. Companies like MycoWorks and Bolt Threads are developing textiles from mycelium, the root-like network of fungi. Mycelium can be grown rapidly on agricultural waste, producing flexible, strong material that mimics leather. Other innovators are turning crustacean shells into a material called chitosan that replicates the texture of leather and suede without any petroleum. These alternatives remain niche, but they point toward a broader range of raw materials for cloth in the coming years.