Fibre Guide

Fibre content decides more about a finished piece than most people budget time for when yarn shopping — warmth, stretch, drape, and how forgiving the fabric is of a slightly uneven hand. Weight category tells you gauge; fibre tells you almost everything else.

The three questions that actually narrow it down

Does the piece need to stretch to fit? Anything relying on negative ease (ribbed cuffs, socks, fitted brims) wants a fibre with real elastic recovery — animal fibres, wool especially, lead here. Does it need to survive a washing machine? Superwash wool, cotton, and synthetics handle regular machine washing far better than untreated animal fibres. Does warmth or breathability matter more? Animal fibres trap air and run warm; plant fibres like cotton and linen breathe and run cool.

Animal, plant, and synthetic — the broad families

Animal fibres (wool, alpaca, mohair, cashmere, angora, silk, yak, camel) generally offer the most elasticity and warmth, at the most care sensitivity. Plant fibres (cotton, linen, hemp, bamboo) are breathable, inelastic, and typically low-maintenance. Regenerated cellulose fibres (bamboo/viscose, Tencel/lyocell) split the difference — plant-derived but processed into a softer, more fluid strand. Synthetics (acrylic, nylon blends) trade some of wool's natural behavior for machine-washability and lower cost, and blends of any of the above aim to combine specific strengths.

Every fibre named above now has its own full profile:

• Animal: Wool, Merino, Alpaca, Mohair, Cashmere, Angora, Silk, Yak, Camel
• Plant: Cotton, Linen, Hemp
• Regenerated cellulose: Bamboo (viscose), Tencel (Lyocell)
• Synthetic: Acrylic
• Common blends: Superwash wool, Wool/acrylic, Cotton/acrylic, Wool/silk, Acrylic/nylon

If you're substituting one fibre for another

Matching weight category isn't enough on its own — see the yarn substitution guides for the specific pairs covered on this site, and always swatch the actual substitute before committing a full project to it.

FAQ

Is a blend always a safer choice than a pure fibre? Not automatically — a blend is a genuine trade-off (some of each fibre's strengths, some of each fibre's weaknesses), not a strict upgrade. A pure fibre chosen deliberately for the trait a project actually needs often outperforms a blend chosen for general safety.

Which fibre is most forgiving for a first project? Wool or a wool blend, generally — its elasticity forgives uneven tension in a way inelastic fibres like cotton and linen don't, and it blocks well if a swatch or finished piece needs reshaping.