Silk: Fibre Guide for Knitters and Crocheters

Silk is a protein fibre, produced by silkworms, which technically puts it in the same broad family as wool — but silk has none of wool's crimp, and behaves almost like a natural counterpart to a smooth synthetic rather than anything resembling sheep's wool in hand or performance.

Strength and sheen, not stretch

Silk fibre is remarkably strong relative to its weight — historically prized for exactly that durability alongside its natural sheen — but it has very little elasticity or recovery, closer to silk's fellow non-crimped fibres like cotton and linen than to wool. A garment relying on negative ease to fit snugly won't get meaningful help from pure silk the way it would from wool.

Why it's usually a blend component, not the whole yarn

Because pure silk yarn is expensive, occasionally heavy in larger pieces, and lacks structural elasticity on its own, it's most commonly blended in a modest percentage with wool or another animal fibre — enough to add real sheen, drape, and a slight lustrous halo, while the base fibre still supplies most of the yarn's elasticity and price-per-skein practicality. See the wool/silk blend page for how that specific combination behaves.

Mulberry versus tussah silk

Mulberry silk (from silkworms fed exclusively on mulberry leaves) is the finer, whiter, more lustrous type most commonly used in yarn. Tussah silk (from wild silkworms with a more varied diet) is coarser and naturally golden-toned, with a more textured, less uniformly glossy look — a real difference worth checking on a label if a specific sheen or color is the goal.

How silk fibre is actually harvested

Traditional silk production unwinds the continuous filament from a silkworm's cocoon, which is what produces silk's characteristically long, smooth, strong strand — a genuinely different fibre structure from the short staple fibres (wool, cotton) spun together to form most other yarns. "Peace silk" or "Ahimsa silk" refers to a production method that lets the moth emerge before the cocoon is processed, at the cost of breaking the filament into shorter lengths and producing a slightly less uniform yarn than conventional silk production.

Care

Hand wash in cool water; silk fibre can weaken with prolonged direct sun exposure over time, so store and dry finished silk pieces out of strong, sustained sunlight. It's a genuinely delicate fibre relative to wool's resilience, worth handling with real care during both use and washing.

Where it's used

Luxury shawls and wraps, where drape and sheen are the entire design point, wool-silk sock and shawl blends adding subtle luster to a practical base fibre, and small-percentage blends in otherwise ordinary yarns specifically to lift the finished look without silk's full cost or care demands.

FAQ

Is silk warm? Moderately — it insulates reasonably well for its weight but doesn't trap air the way wool's crimp does, so it reads as a moderate rather than a genuinely warm fibre on its own.

Does silk use more or less yarn than wool at the same weight category? Actual yardage per gram varies by how densely a specific silk yarn is spun, the same caveat that applies to any fibre comparison at a shared CYC category — always check the specific ball's stated yardage rather than assuming a fixed relationship.

Can silk be machine washed? Not recommended for most silk and silk-blend yarns — hand washing is the safer default, even for blends where the majority fibre is otherwise machine washable.

Does silk block the way wool does? Not in the same reshaping way — silk lacks wool's crimp, so blocking evens out stitch tension without the dramatic opening-up effect blocking gives lace worked in a crimped animal fibre.