How to Block Your Knitting (and When You Should, Shouldn’t, and Definitely Need To)
Last year, I finished knitting a vest for my daughter.
I was feeling pretty pleased with myself… and she looked at me and said,
"Are you going to block it?"
Now, she doesn't knit.
But thanks to the internet, she knew something I had completely ignored for years.
Because when I first learned to knit, blocking just… wasn't a thing we talked about. Not like it is now.
So that vest?
That was the first garment I ever properly blocked.
And since then, I've learned a lot. Some of it the easy way. Some of it… not.
This guide is everything I wish someone had explained earlier.
What is blocking (and do you actually need to do it?)
Blocking is simply the process of:
Getting your finished knit wet or damp
Letting the fibres relax
Shaping it into the size and structure you want
Letting it dry in that shape
That's it.
But the impact?
It can take something that looks a bit uneven, a bit "homemade"…
and turn it into something that looks polished, intentional, and properly finished.
Do you have to block?
No.
But…
It evens out stitches
It improves drape
It sets the shape
It makes your garment look like the pattern photo
So while it's optional… it's also the step that makes everything look better.
The most important thing: blocking is NOT the same for every yarn
This is where people go wrong.
There is no "one right way" to block.
How you block depends entirely on the fibre. If you're not sure what fibre you're working with, our guide to choosing the right knitting yarn is a good place to start.
🧶 Wool (non-superwash)
This is the classic. New Zealand wool in particular responds beautifully to blocking.
Loves a soak
Responds beautifully to blocking
Holds its shape once dry
This is where full wet blocking works best.
🧶 Superwash wool
Proceed with caution.
Superwash can stretch. A lot.
If you:
Over-soak
Lift it carelessly
Let the weight pull it down
…it can grow. Dramatically.
Sometimes people think blocking "ruined" their knit.
It didn't.
It just behaved exactly how superwash behaves.
🧶 Mohair and alpaca
Beautiful. Dangerous.
These yarns have very little memory.
Which means:
They drape beautifully
They stretch easily
They don't bounce back
For these, I often recommend steam blocking instead of soaking.
Because once you stretch them too far… that's where they stay.
(Ask me how I know.)
🧶 Cotton
Completely different again. For a deeper dive, read our guide on everything you need to know about cotton yarn.
Cotton:
Doesn't have memory
Doesn't "spring back"
Can shrink
Blocking isn't about reshaping as much as it is about setting after washing.
Often, a gentle machine wash + flat dry is more appropriate than traditional blocking.
🧶 Acrylic
You don't really "block" acrylic.
You can:
Wash it
Shape it
But it doesn't respond to blocking in the same way natural fibres do.
How to block your knitting (step by step)
This is the method I use most often for wool and similar fibres. You'll need a few basic knitting accessories — blocking mats and pins make a big difference.
1. Soak your garment
Fill a basin with lukewarm water and add:
Wool wash
Or baby shampoo
Gently press your garment into the water. Don't agitate it.
Leave it for:
15–30 minutes max
2. Remove excess water (gently)
This is where people ruin things.
Do NOT wring
Do NOT twist
Do NOT lift it dripping wet
Instead:
Let water drain
Gently press it against the sink
Or place it in a colander
3. Towel roll (my favourite step)
Lay your garment on a towel.
Roll it up like a sausage.
Then:
👉 Stand on it
👉 Press along the roll
This pulls out a surprising amount of water.
4. Lay it flat and shape it
Now the real blocking begins.
Lay it on towels or blocking mats
Shape it with your hands
Straighten edges
Set sleeve positions (I use a T-shape for sweaters)
If needed:
Use pins to hold shape
Especially if you're stretching or adjusting fit
5. Leave it alone
Walk away.
Usually 1–2 days
Longer if it's cold or damp
Once dry, the shape is set.
Common blocking mistakes (I've made most of these)
"My garment grew!"
Usually:
Superwash yarn
Too much water
Lifted while heavy
I've had mohair grow by about 30%.
Still wearable. Definitely not planned.
"It looks weird after drying"
Often:
Not shaped properly
Towel wasn't flat
Didn't straighten edges
(Yes, I have a jumper with a permanent crease from this.)
"Blocking ruined it"
Usually not.
Blocking just revealed:
Gauge issues
Yarn behaviour
Or a mismatch between yarn and pattern
Understanding yarn weight, ply, and metreage before you cast on can help avoid these surprises.
How often should you wash (and re-block)?
Less than you think.
Wool is naturally self-cleaning.
Most garments:
Don't need frequent washing
Can be aired instead
When you do wash:
Lay flat to dry
Reshape each time
That alone is a form of blocking.
Can you machine wash hand knits?
Now we get to the question everyone asks.
Yes… sometimes.
Untreated wool → No
Superwash wool → Gentle cycle only
Acrylic → Usually fine
Cotton → Yes, but may shrink
Blends → Check the label
Important:
Even if you can machine wash it…
you still want to dry it flat and reshape it.
A few final things I always tell customers
Don't hang knits to dry. They will stretch
Don't hang them in your wardrobe either. Fold them
Add a cedar block if you can (moths are real)
Always include care instructions if gifting
The real goal here
Blocking isn't about perfection.
It's about helping your knitting become what you imagined it would be.
And like everything in knitting…
you'll learn most of it by trying, adjusting, and occasionally getting it wrong.
And that's completely fine.
Ready to start your next project? Browse our yarn collections — or read more about how we choose the yarn we stock.
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