Blocking is the magical alchemy that transforms your crumpled pile of tensioned stitches into a garment that actually fits a human. But ask five knitters how they block, and you’ll get seven answers, a warning about mohair and probably a tale of a lace shawl that grew to cover the dining table and the neighbour’s cat.

What is the “right” way to block your knitting?

The truth is it depends entirely on your yarn. Alpaca doesn’t want what cotton wants, and merino behaves differently to mohair. So I thought I’d walk us through blocking fibre by fibre, and I’ll round up the trusty tools I can’t block without right at the end.

Wool (Merino, Bluefaced Leicester, Shetland, etc.)

Best blocking method: Wet blocking

Good old-fashioned wool loves a soak. It blooms beautifully and holds its shape like a dream after a proper wet block.

How to:

• Fill a basin with lukewarm water and a bit of no-rinse wool wash.
• Let your garment soak for 20 minutes. Don’t agitate it too much, just let it do its thing.
• Lift it out carefully (no wringing, unless you enjoy felting), roll in a towel to remove excess water and pin into shape on your blocking mats.

Why it works:
The soak lets the fibres relax and re-align, smoothing out tension and helping the stitches settle evenly. Ideal for lace, cables and anything needing a bit of drape.

Watch out:
Steam blocking works okay for wool, but can flatten texture if you’re not careful. Wet blocking gives a full reset without any drama.

Alpaca

Best blocking method: Wet block gently, or use steam if in doubt

Alpaca has no crimp (the bounce you get from wool), so it won’t spring back. Overblock it, and your cardigan suddenly becomes a dress.

How to:

• Wet block very gently: give it a short soak, with no stretching.
• Alternatively, lay flat and lightly steam by hovering your iron over it, not touching the fabric. Just a bit of gentle heat to settle the stitches.

Why it works:
Alpaca fibres are smooth and heavy, which means they drape beautifully, but they don’t bounce back like wool. Gentle blocking helps shape the fabric without stretching it beyond reason. Steam is often safer, as it gives you a bit of control without soaking the life out of it.

Watch out:
This is not the fibre to block aggressively. No tugging, no pinning it like a murder scene. Let it find its shape, and coax it if needed.

Superwash wool

Best blocking method: Wet block, but watch the drape

Superwash wool can be slippery. Literally. It’s been treated to resist felting, which also means it’s less elastic and more prone to stretching out.

How to:

• Wet block, but don’t over-soak. Support the weight when lifting it out of water.
• Pin it to size, not beyond and never hang while wet.

Why it works:
You still need that soak to smooth out tension and even out the fabric, but you need to set boundaries with superwash yarns. Give it an inch and it will take a mile, and you’ll end up swamped in your oversized, misshapen garment.

Watch out:
Steam blocking can flatten superwash rather than help shape it, so wet blocking is more effective, but keep a measuring tape handy.

Cotton + linen

Best blocking method: Wet block, then steam or press to finish

These plant fibres have zero elasticity. You’re not “relaxing” them so much as ordering them to behave. Best practice here is wet blocking to give you the initial shape, then steam or pressing to help lock it in.

How to:

• First, give your garment a full wet block: soak in lukewarm water, gently squeeze, lay flat and pin to measurements.
• Once dry, lightly steam or press seams, hems and collars to sharpen them up.

Why it works:
Water gets the fibres to relax and settle, but the steam or iron finishes the job. There’s nothing quite like a crisp neckline, nice obedient button bands and hems that don’t roll like a croissant.

Watch out:
Don’t skip the pressing stage if you want that polished, handmade-not-homemade look. And never press directly on – use a cloth or muslin layer to protect your fibres from direct heat.

Mohair + other brushed fibres (angora, suri lace)

Best blocking method: Steam blocking only

I don’t recommend wet blocking mohair unless you want to spend the next three hours detangling a halo that looks like an angry hedgehog. (As an aside, I still wet block anything where I’ve held mohair or a brushed yarn double with a wool, like merino for example, as they don’t seem to react as badly when paired this way.)

How to:

• Lay flat and steam with a hovering iron.
• Use your hands to lightly smooth it into shape, but don’t squash it, to preserve the fluff!

Why it works:
Steam relaxes the fibres without soaking them, which keeps that ethereal floaty texture intact. This gentle method also prevents aggressive flattening or the dreaded felting.

Watch out:
Too much moisture = matted disaster. Keep things light and airy. Less is definitely more when it comes to these fibres.

Acrylic

Best blocking method: Steam block (with caution), or try “killing”

Yes, killing. And no, I don’t mean shoving it in a drawer and pretending it never happened.

How to:

• Lightly steam block by hovering the iron. Never touch it directly or you’ll melt your jumper into a placemat.
• For dramatic drape (and permanence), you can deliberately “kill” acrylic: steam heavily until it relaxes and stays put forever. No going back.

Why it works:
Acrylic doesn’t “remember” shape very well with water alone, so heat is the key to getting it to relax. But use this technique with caution! Don’t kill something you love unless you really mean it. Once “killed”, it won’t bounce back.

Blocking tools I swear by

Here’s my short list of can’t-do-withouts when it comes to steam or wet-blocking:

• Blocking mats – foam interlocking ones are fab (kids’ play mats also work a treat)
• Stainless steel T-pins – rust-free, sharp and strong enough to shape your chunky knits
• Wool wash – I love a no-rinse formula with a soft scent (Eucalan eucalyptus and lavendar or Soak are my personal favourites)
• Steamer or steam iron – one with a good hover function (and an off switch you trust)
• Blocking wires – brilliant for precision-shaping straight edges and lace
• Spray bottle – for misting small areas or coaxing curls into shape

Final thoughts

Blocking isn’t a dark art, though it can seem like that sometimes. While the internet is awash with very strong opinions, it all comes back to knowing your fibre and giving it what it needs – be that a good long soak, a cautious hover of the iron or some serious stretch, pin-and-pray energy.

And if you’re still not sure? If in doubt, gently wet block first. It’s the Swiss Army knife of finishing techniques.

Beth x