Yarn Substitutions
Substituting one yarn for another isn't just a weight-matching exercise — fibre content changes elasticity, blocking behavior, warmth, and care, and a pattern's fit logic can depend on assumptions the new fibre doesn't share. This section covers specific, real substitution pairs rather than a generic "how to substitute yarn" checklist.
How these guides are chosen
Each page here covers a substitution pattern crafters genuinely search for — not every fibre paired against every other, which would produce hundreds of thin, mostly-irrelevant combinations. Can You Substitute Acrylic for Wool? is the most common of these swaps, driven by cost, allergy concerns, and machine-washability.
Every pair covered
- Acrylic for wool and wool for acrylic — the most-asked swap, run both directions
- Cotton for acrylic — trading acrylic's modest stretch for cotton's crisp, inelastic stitch definition
- Alpaca for wool — real warmth and drape gains, at the cost of wool's active elasticity
- Cashmere for Merino — the gentlest swap on this site, between two already-similar fine wool-family fibres
- Silk for cotton and bamboo for cotton — trading cotton's crispness for drape and sheen, two different ways
- Linen for cotton and hemp for linen — the bast-fibre family, softness against durability
- Mohair for wool and angora for mohair — halo fibres, almost always held with a companion strand
- Superwash wool for untreated wool — the closest swap on this site, still wool on both sides
- Wool/acrylic blend for pure wool and acrylic/nylon blend for plain acrylic — blends replacing their own base fibre
- Tencel (Lyocell) for bamboo — two regenerated-cellulose fibres, same hand, different manufacturing footprint
- Camel for yak — two specialty down fibres from animals built for extreme cold
What changes in nearly every substitution, regardless of the specific pair
Elasticity. Swap an elastic animal fibre for an inelastic plant or synthetic one and any part of the design counting on negative ease to fit snugly — a ribbed cuff, a sock, a fitted brim — will behave differently, sometimes enough to need a different stitch pattern or ease amount entirely. Blocking. Not every fibre responds to wet or steam blocking the same way; a substitution that changes blocking behavior can change a lace or cable pattern's final look as much as it changes the yarn itself. Yardage per gram. The stated weight category is a gauge range, not a promise about actual yardage — check the specific ball band on both yarns rather than assuming "same category" means "same amount of yarn."
Before you commit yarn to a full project
Swatch the actual substitute, in the actual stitch pattern, and compare against the pattern's stated gauge — not just the weight category. A gauge mismatch doesn't have to end the substitution: the Gauge Conversion Calculator rescales whatever the pattern expects into what your own swatch actually produced, before a single skein gets committed to finding out by hand.
Related reference
The fibre guide covers each fibre's own characteristics in depth — read the specific fibre pages for both sides of a substitution before trusting this section's pairing-level advice alone.
FAQ
What if the exact substitution I need isn't covered here yet? Use the general principles above (elasticity, blocking, yardage-per-gram) alongside the individual fibre pages for both yarns — the same reasoning applies even to pairs without a dedicated guide.
Is matching weight category enough to guarantee a substitution works? No — two yarns in the identical CYC category can still produce different gauges and noticeably different fabric behavior. Weight category narrows the search; swatching confirms it.