Fiber content on apparel and most household textiles is a federal labeling job. The Textile Fiber Products Identification Act is the statute. FTC business guidance is the readable version. Craft Yarn Council standards are for yarn weights, not woven yardage, useful when a spool or a ball sits next to the bolt.
Named fibers
| Name | Family | Usual tell |
|---|---|---|
| Cotton | Natural cellulose | Absorbent, wrinkles, takes a hot iron when the care label allows. |
| Linen | Natural cellulose (flax) | Crisp hand, visible slub, wrinkles hard. |
| Wool | Natural protein | Resilient; care label may say dry clean or hand wash. |
| Silk | Natural protein | Fine filament; often dry-clean on the label. |
| Rayon / viscose | Manufactured cellulose | Drapes; weak when wet, read the care label before you wash. |
| Polyester | Synthetic | Strong, low wrinkle; heat can glaze it. |
Blends must list generic names and percentages. If the bolt end and the care label disagree, believe the sewn-in label on a finished garment and the bolt end on uncut cloth. Do not invent a shrink percentage. Storage in Florida humidity is a separate page.