Getting Gauge in Natural Fibres: Secrets and Subtleties
Natural fibres like alpaca, silk, and mohair don’t always behave like you expect. That’s why getting gauge right is crucial. With high-end yarns, even a perfect swatch can shift. Know your fibre, block properly, and swatch smart to make sure your finished piece fits beautifully.
You swatch, you count, you block—and still, your sweater ends up with sleeves that could double as wings. Sound familiar?
Even the most seasoned knitters have whispered curses at a gauge gone rogue—especially when using natural yarns. They behave differently, and that's exactly what makes them so special… and so tricky.
If you’ve ever wondered why your laceweight alpaca blooms like a wildflower or why your silk blend doesn’t stretch the way you expect, this one’s for you. Grab a cuppa—let’s get deep into the subtleties of gauge when working with top-tier yarn.
What Is Gauge - and Why It Matters (Still!)
We know, we know. You've been knitting for decades. You know what gauge is. But let’s do a 30-second refresher anyway:
Gauge is the number of stitches and rows per 10cm (4") of knitting. It determines:
- The fit of your garment
- How the fabric behaves (drapey, dense, bouncy, etc.)
- Whether you run out of yarn halfway through the second sleeve (don't ask…)
When working with high-end fibres, gauge becomes even more important—because the yarn’s characteristics are amplified. A little extra drape in a silk-blend shawl? Lovely. A saggy cashmere jumper? Less so.
Why Natural Yarns Don’t Always Play by the Rules
natural yarns often contain blends of natural fibres—Merino, alpaca, silk, mohair, yak, cashmere—and those fibres all react differently to:
- Blocking
- Needle material
- Knitting tension
- Environmental conditions (yes, really)
1. Fibre Memory (Or Lack Thereof)
Merino has great elasticity. Silk? Not so much. Alpaca? It stretches like your nan’s Christmas pudding recipe.
The takeaway? Your blocked swatch might look perfect today but grow considerably over time. That’s not a fault—it’s a fibre feature. The trick is to anticipate it.
Top tip: Knit a swatch that’s at least 15x15cm, wash it exactly as you will your finished object, pin it out, and then wait. Overnight at least. Two days, even better. Measure your gauge after it’s settled, not straight off the needles.
2. The Bloom Effect
Yarns with a halo—think brushed alpaca, mohair, or blends like Walcot Yarns Opus—will often “bloom” after washing. That means they puff up, fill in gaps, and change the gauge.
If you knit a lacy design and don’t account for bloom, the stitch definition can disappear like last year's limited-edition yarn. Beautiful? Yes. Predictable? Not without swatching.
Top tip: Don’t rely solely on the pre-block gauge. Block. Let bloom. Re-measure.
3. Silk and Drape
Silk blends tend to lengthen with wear. If your gauge is spot on horizontally but your rows are off vertically, you may end up with a tunic when you wanted a tee.
Silk also affects stitch definition—it can flatten stitches slightly, giving a sleek, polished look but making mistakes more visible.
Top tip: For garments, aim for a slightly firmer fabric than you think you need. That extra support helps garments keep their shape.
4. Needle Material Matters (Yes, Really)
The friction between yarn and needle can dramatically affect your tension, so the needles you choose can have a direct impact on your completed swatch.
- Metal needles often create a looser gauge—yarn glides effortlessly.
- Wood or bamboo offer more grip, which may tighten your tension slightly.
- Carbon fibre, like ChiaoGoo’s, can strike a beautiful balance between slick and steady.
If your swatch is off and you’ve tried changing needle size without joy, consider switching needle material, not just millimetres.
Common Gauge Pitfalls in natural Yarn (and How to Avoid Them)
Let’s look at a few “classic” natural yarn surprises and how to swerve them with grace.
❌ You knit a garment in alpaca. It fits… for a week. Then it’s huge.
Why? Alpaca lacks bounce and stretches with gravity.
Fix it: Choose designs with structure (think: seams). Consider going down a needle size or blending with a more elastic yarn like Merino. Swatch big and let it hang before measuring.
❌ Your silk-blend cardigan is stunning but slips off your shoulders.
Why? Silk adds weight and drape—great for shawls, trickier for fitted garments.
Fix it: Add shoulder shaping, stabilising seams, or use a firmer gauge to give the fabric more resilience.
❌ You bought a mohair blend and your lace pattern disappeared.
Why? That gorgeous halo blurred the stitch definition.
Fix it: Choose simpler textures when working with haloed yarns—or embrace the fuzz and let the fabric shine in its softness.
The Swatching Checklist
Before committing your £30 skein to that heirloom jumper, work through this swatch ritual:
- Swatch larger than 10x10cm
- Use the actual stitch pattern of the project
- Wash as you would the FO
- Block as you will block the FO
- Wait at least 24 hours post-block to measure
- Hang vertically if knitting garments with heavy yarn
- Note gauge AND fabric feel (Is it drapey? Dense? Floppy?)
- Try different needles if tension seems off
This may feel like a chore—but remember: the yarn is an investment. A swatch is your insurance policy.
Ask Yourself: “What Do I Want This Fabric to Do?”
When knitting with high-end yarn, don’t just chase gauge—chase intent. What do you want this fabric to feel like? To do? Drape like liquid or hold its shape like sculpture?
Designers give gauge as a tool to help you ensure that your finished garment is the same size as indicated in the pattern, however, the materials you use, from the composition of the yarn, to the material of your needles, will all affect your final fit.
You can use the same materials as the designer, or make your own substitutions, follow the pattern to the letter, or make your own modifications - be that a shorter hem or wider neckline - just remember, meeting gauge is the best way to ensure you are left with a finished piece that fits the bill.
“Gauge is like a handshake between designer and knitter. It's your job to make sure it fits your hand.” – Someone probably very wise
Happy knitting,
~ Carmen