Read a clothing label and you are really reading two families of fibre. Natural fibres come from plants and animals: cotton, linen, wool, and silk. Synthetics are spun from petrochemicals: polyester, nylon, and acrylic. Sitting between them are the semi-synthetics, such as viscose and lyocell, made by chemically processing natural cellulose from wood pulp. Each family behaves differently on your body and in the wash, and the popular shorthand that natural is good and synthetic is bad does not survive close reading.
The honest way to compare fabrics is by behaviour, not reputation. Here is how the common fibres stack up on the things you feel day to day.
| Fibre | Breathability | Durability | Care | Rough cost |
|---|---|---|---|---|
| Cotton | High | Good, wrinkles | Easy, shrinks hot | Low to mid |
| Linen | Very high | Very good, creases | Easy, air-dry | Mid |
| Wool | High, warm | Excellent | Gentle, can felt | Mid to high |
| Silk | High | Delicate | Hand-wash / dry-clean | High |
| Polyester | Low | Very high | Easy, fast-dry | Low |
| Nylon | Low | Very high | Easy | Low to mid |
| Viscose | Mid to high | Weak when wet | Fussy, often dry-clean | Low to mid |
| Lyocell | High | Good | Easy, washable | Mid |
Natural fibres tend to breathe. Cotton and linen let air and moisture move, which is why they feel cool in heat, and linen in particular is prized for hot weather. Wool is the outlier: it insulates, resists odour, and recovers its shape, making it one of the most durable everyday fibres you can buy. Silk is luxurious and breathable but genuinely delicate. The trade-off across the group is care and creasing. Cotton and linen wrinkle, wool can felt if washed hot, and silk often needs hand-washing or the dry-cleaner.
Synthetics were engineered to solve real problems, and they do. Polyester and nylon are strong, hold colour, dry fast, and resist wrinkles, which is why they dominate sportswear, outerwear, and anything that has to take a beating. Acrylic mimics wool at a lower price. The classic downsides are breathability and odour: petroleum-based fibres trap heat and hold smell, so a polyester shirt on a hot day is rarely comfortable. Their biggest environmental catch is microfibre shedding. Textile researchers and environmental agencies report that synthetic garments release tiny plastic fibres in the wash, and those microfibres end up in waterways because treatment plants do not fully capture them.
It is tempting to read natural as clean and synthetic as dirty, but the picture is messier. Conventional cotton is thirsty and, when grown intensively, relies heavily on pesticides. Viscose is technically plant-based, yet the chemical process that turns wood pulp into fibre can be polluting unless it is done in a closed-loop system, as the newer lyocell process is. Meanwhile a durable polyester coat that lasts a decade may do less harm over its life than a cheap cotton tee replaced every year. The fibre label alone does not settle the question.
What matters more is how long a garment lasts and how you treat it. A well-made piece in almost any fibre, worn for years, beats a poorly made one you discard quickly, a point at the heart of slow fashion. If you want a practical shortlist by use case, our guide to the best fabrics for everyday clothes translates these trade-offs into buying decisions, and both natural and synthetic pieces last far longer once you care for them properly.
For summer and next-to-skin wear, lean natural: cotton, linen, and lyocell breathe and feel better. For activewear, rain gear, and hard-use items, synthetics earn their place on strength and speed of drying. For warmth and longevity, wool is hard to beat. And blends exist precisely because they borrow strengths from both sides, so a cotton-polyester shirt trades a little breathability for less ironing.
The bottom line: natural fibres generally breathe better and biodegrade, synthetics generally last longer and dry faster but shed microfibres. Neither family is automatically greener. Judge a garment on how it is made, how long it will last, and how you will care for it, not on the fibre name alone.