Every fabric decision starts with the fibre. The fibre decides how a garment feels, how it dyes, how it shrinks, how it pills and what it costs. This guide covers the fibres a garment factory meets most often.
The three families
- Natural fibres come from plants or animals: cotton, linen, wool, silk. Cotton dominates everyday apparel.
- Regenerated fibres are made from natural cellulose that is dissolved and re-formed: viscose, modal, lyocell. They are neither fully natural nor fully synthetic, and they behave like cotton in many ways, including strong shrinkage and low wet strength in basic viscose.
- Synthetic fibres are made from petrochemical polymers: polyester, nylon (polyamide), acrylic and elastane (spandex).
How the main fibres behave
- Cotton. Absorbent, comfortable, takes dye well, easy to sew. It wrinkles, shrinks in the wash if not pre-treated, and dries slowly.
- Polyester. Strong, light, dries fast, holds shape and resists wrinkles. It absorbs little moisture, so it can feel warm and hold odour, and it is dyed with a different dye class from cotton. Heat-sensitive: too much iron or press temperature leaves a shine or marks.
- Viscose. Soft, drapey, silky hand. It is weak when wet, shrinks and distorts easily, and needs gentle handling in cutting and washing.
- Nylon. Very strong and abrasion resistant, used in activewear, hosiery and outerwear.
- Elastane. Added in small percentages to give stretch and recovery. It is rarely used alone; it is wrapped or plated with another yarn.
- Wool. Warm and elastic, but needs careful finishing and care instructions to avoid felting.
Why blends exist
A blend combines strengths and hides weaknesses. Polyester added to cotton improves strength, wrinkle resistance and drying time. Cotton added to polyester improves comfort. Two terms you will see on orders:
- CVC (chief value cotton): cotton is the larger share, for example a cotton-rich blend.
- T/C (polyester-cotton): polyester is the larger share.
The exact ratio is on the specification and must match the label. Fibre content on a care label is a legal declaration in many markets, so a blend that tests differently from its label is a compliance problem, not only a quality one.
Mistakes to avoid
- Treating a blend like its main fibre. A cotton-poly fabric needs different dye processes and different press settings from pure cotton.
- Ignoring heat limits. Synthetic content sets the safe pressing temperature, not the natural content.
- Forgetting pilling. Loose short fibres rolling into balls on the surface are most visible in polyester blends and in low-twist yarns. Yarn quality and finishing matter more than the fibre name alone.
- Mixing lots with different fibre ratios in one garment or bundle, which gives visible shade and hand differences.
A short checklist before approving a fabric
- Fibre content confirmed on the mill's documents, and on the order.
- Dye class suits every fibre in the blend.
- Pressing and fusing temperatures set for the most heat-sensitive fibre.
- Shrinkage and pilling tests requested where the buyer requires them.
For how the yarn itself is made and why it changes fabric quality, read combed vs carded cotton.
A practical note on sourcing: ask the mill for a fibre content test report for each lot, not only a statement on the invoice. For cotton-polyester blends, the actual ratio can drift between lots, and the drift shows up later as shade difference, different shrinkage or a different hand feel. For garments with elastane, ask for the percentage and the recovery result, because a little too much or too little changes fit and the way seams behave. Keep the approved fibre details on the tech pack and repeat them on the label so that the factory, the buyer and the end customer all see the same declaration.