What each natural fiber is, how it becomes fabric, how it wears, and what to check on the label. Every claim is sourced, industry-funded sources are flagged, and each guide lists its drawbacks.
Plant fiber from the stalk of the flax plant (a bast fiber).
Linen is the classic summer fabric: crisp, quick to dry and long-lasting, and famous for wrinkling. Here is what the evidence says about how it’s made, how it wears, and what the label should say.
Plant fiber from the stalk of industrial hemp (Cannabis sativa L.), a bast fiber like flax.
Hemp is a tough bast fiber with a good environmental story and a reputation for feeling rough. Here is what the research supports, what it doesn’t, and how to read a hemp label.
Animal fiber shorn from alpacas, South American camelids.
Alpaca is sold as warmer and softer than wool. Some of that holds up, some is marketing. Here is what the research and the trade’s own standards say.
Animal fiber: the fine undercoat of the cashmere goat.
Cashmere is soft, light and expensive, and it comes with real questions about grazing, welfare and mislabeling. Here is what the rules and the research say.
Animal protein fiber spun by silkworms, mostly the domesticated Bombyx mori.
Silk is light, smooth and strong for its weight, but it’s damaged by sunlight and most production kills the silkworm. Here is what the sources say.
Plant fiber from the cotton boll, grown under organic farming rules.
Organic cotton is the same fiber as regular cotton, farmed differently. What matters is whether the claim is certified, and fraud has been a real problem.
Cellulose from wood pulp, bamboo or other plants, chemically dissolved and spun into new fiber.
These fibers start as trees or bamboo, so they’re often sold as natural. Regulators classify them as manufactured fibers, and FabricTruth counts them as non-natural. Here is why, and what each name means.
Scores count only natural fibers. Regenerated cellulose such as lyocell or “bamboo” rayon starts as a plant but is chemically dissolved and re-spun, so it counts as non-natural (how scoring works).
| Fiber | Type | Counted as | Guide |
|---|---|---|---|
| Linen (flax) | Plant, bast | Natural | Read |
| Hemp | Plant, bast | Natural | Read |
| Alpaca | Animal | Natural | Read |
| Organic cotton | Plant, seed | Natural | Read |
| Cotton | Plant, seed | Natural | Not yet |
| Wool and merino | Animal | Natural | Not yet |
| Cashmere | Animal | Natural | Read |
| Silk | Animal | Natural | Read |
| Lyocell (Tencel), modal, viscose, “bamboo” rayon | Wood or plant pulp, chemically dissolved and re-spun | Not natural (regenerated cellulose) | Read |
| Polyester, nylon, acrylic, elastane | Synthetic, from fossil fuels | Not natural | Not yet |