The pattern calls for a yarn you can't get — or can't justify. Substitution is normal, but three checks separate a clean swap from a sweater that fits nobody.
Step 1 — Match the weight category
Stay inside the same CYC category (see the weight chart). One category apart can work with needle/hook changes and a fresh gauge swatch; two apart is a different garment.
Step 2 — Check the fiber's behavior
| Fiber | Behavior | Watch out for |
|---|---|---|
| Wool / animal | Elastic, warm, holds shape | Some need hand-washing |
| Cotton / linen | Heavy, crisp stitch definition, zero stretch | Garments grow and droop |
| Acrylic | Durable, budget-friendly, washable | Stretch varies by brand |
The classic mistake: substituting cotton for wool in a fitted garment. The fabric relaxes with wear and the fit walks away.
Step 3 — Swatch, then buy
Work a 4×4 in swatch in the substitute. If you're getting fewer stitches per inch than the pattern, go down a needle/hook size; more, go up. Only buy the full quantity once the swatch matches.
Recount the skeins
Your substitute's skeins almost certainly hold different yardage than the original's. Total yardage ÷ new yards-per-skein, round up, add ~10–15%. SkeinSense's Substitution tool does this comparison in one screen — including whether the swap is compatible at all.
Check a substitution in seconds — free in SkeinSense →