How and why to block knitting and crochet

When one of my craft group asked, ‘What’s this blocking thing you talk about on your blog?’ My ‘brief’ explanation had many many points. Since I’d just finished crocheting my Eva Shawl, I decided to write a post about blocking crochet and knitting using Eva as my model. So, here’s how and why to block knitting and crochet.

Eva's Shawl

Why block knitting and crochet?

Blocking has several beneficial effects on your knitting or crochet. It can:

  • ‘Iron’ out uneven stitches and tension issues.
  • Allow you to shape a garment the way you want it.
  • Help your garment keep it’s shape over time.
  • Improve the look and drape of your fabric.
  • Make seaming easier

How to block knitting and crochet

How you block will depend on the composition of the yarn you’ve used, on what you’ve made, and the techniques you’ve employed to make it. I’ll cover that in detail shortly, but first I’ll cover the basic methods used for blocking.

Basic blocking methods

The three basic ways to block are wet blocking, steam blocking and spritzing. I usually wet block, because I usually work with wool or yarn with a high percentage of wool. I also find it the easiest way for larger pieces.

Wet blocking

  • Add wool wash – or suitable detergent to a bowl big enough to comfortably hold your work.
  •  Check care label on your yarn for suitable wash temperature and fill your bowl with water of the appropriate temperature.


  • Place you fabric in the bowl, pushing it under the water and squeezing gently to help the water penetrate.
  • Leave for 20 minutes – although longer is fine – to allow the water to fully penetrate the fibres.
  • While your fabric soaks, gather together a towel of similar dimensions to your work, blocking mats and pins.
Blocking matts
  •  When your knitting or crocheted piece has soaked long enough, gently lift out, supporting it so that the weight of the water doesn’t distort the fabric. If your wool wash doesn’t require rinsing out, squeeze the water out gently. If your wash requires rinsing, rinse in a bowl of fresh water. Do not run wool directly under the tap as this can cause it to felt.
  • When you have squeezed the water from your work – never wring or twist as wet wool is fragile and this will damage the fibres – roll in a towel to remove excess water. I usually to stand on mine to take out as much as possible.
  • Unroll the towel and lay your knitted or crocheted piece flat on the blocking boards.
  • Pin out your piece in the desired shape, using a tape measure to get the dimensions you want. How you pin will depend on how aggressively you want to block your piece. Refer to your pattern and yarn care instructions for greater guidance. The extremes run from lying your piece flat and leaving it, to pinning stretching hard into shape.
  • Leave your work to dry.


Steam Blocking

  • Pin the piece(s) to the required dimensions.
  • Hold steam iron above the work and blast down with steam, forcing the steam through your knitted/crocheted piece. DO NOT touch your work with the iron.
  • Once the fabric is fully drenched, leave it to dry.


  • Pin the piece(s) to the required dimensions.
  • With a spray bottle, spritz each piece until it is damp, but not soaked.
  • Leave to dry.

Blocking different fibres

Animal fibres

Wet block wool – although fine gauge wool is better spritzed if it is very delicate.

Cashmere, merino, alpaca, silk and mohair are all finer, more fragile fibres  than wool, therefore pinning gently and and spritzing is usually best as wet blocking may damage them.

Plant fibres

Cotton is weak when wet and has no memory – which is why it easily stretches out of shape. Highly structured garments are less likely to stretch, so worth a steam blocking.

Conversely Linen is stronger when wet. Wet blocking is therefore ideal and more aggressive treatment necessary if you wish to stretch garment pieces.

100% synthetic fibres

These are usually ruined by heat, so pinning and spritzing are the best way to go with these.

Mixed fibres

It’s usually best to err on the side of caution and pin and spritz. However, if there is very high percentage of wool, wet blocking may be appropriate.

Well that’s my summary of blocking. For further information read my post Ten Top Tips About Blocking Knitting and Crochet.

Hope you find this useful and let me know if you’ve anything to add that I haven’t thought of.

Thanks for reading.

Bekki Hill


36 thoughts on “How and why to block knitting and crochet

  1. Thanks for this, Bekki! I have been stalling the blocking process since quite a while fearing what might happen. But I shall try it soon. Since I work with acrylic fibers mostly, I had gone through tips on how to steam block. But then again, I had also read that its best to throw acrylics into the washer/dryer to even out the tension. But I will try steaming a sample today and see how it turns out. Practice makes perfect 🙂

    Liked by 1 person

    1. I think blocking is one of those things that sounds far scarier than it is. I’d agree, most synthetic yarn doesn’t really need blocking – as you can’t set the fibres like you can with wool. Well unless you get it too hot and ruin it. Good luck wuith the steaming! 🙂


  2. Very useful Bekki. I do block – but usually use the spritzing method as I find it less ‘scary’ than full immersion which takes days to dry sometimes. Also, I block the finished garment rather than the pieces. I find opinion appears to be split on that point with others blocking each piece as you suggest and I can imagine that it would make seaming easier so maybe I’ll try that next time.
    However, unquestionably, blocking does make a huge difference. My Mum never blocks anything – nor does my sewing/knitting buddy – and I have to say that the garments they make never have that ‘finished’ look that blocking gives you. (I don’t ‘have to say’ it to them of course – I value my life too much!!)

    Liked by 1 person

    1. Ha ha! Yes better not pointed out, and if they’re happy, does it matter? I like full immersion with bigger things as I have more patience to wait for things to dry than to stand over them with and iron or water spray. I don’t always block in pieces, but I do find the two dimensional aspect of pieces often easier that the 3d-nessof a full garment.


    1. Hi Mary, yes to an extent, because you will set a memory in the yarn when you initially block it to size. The fibres will however relax each time you wash it, so some changes will still occur. And of course, if you go wash it to hot it will still shrink 🙂


  3. Thank you for this information. I have to admit that I have not practiced any blocking. (Gasp!) I know, I know. It’s kind of like not pressing when sewing. (I do press, I promise) I guess that because I am such a slow knitter that I’m feeling too overdue so I jump right in and use it. What about socks? Should they be blocked?

    Liked by 1 person

    1. Hi Robyn! I certainly don’t think blocking is always necessary and at times is definitely personal choice. I don’t block socks, because they go on your feet and get pushed into shape. The argument it makes them softer doesn’t work for me as they’ll soften when they have their first wash. The only real reasons I see are so they look nice when you give them as a gift or blog about them. Sock blockers are pricey and those don’t seem good enough reasons for the expense. Maybe someone has a good reason, but I haven’t found it yet.

      Liked by 1 person

  4. I block everything I knit. It makes a huge difference in the final product. I think it’s because I use mostly natural fibers with knitting. When I crochet, it’s usually baby/kid blankets and I use acrylics for ease of use for the parent. It’s so easy to just throw in the wash 🙂

    Liked by 1 person

    1. Thank you. This one’s for over the back of my chair at my desk to pop over my shoulders when it’s chilly. What I meant was I’m not a going out in public shawl wearer unless it’s a particularly special occasion.

      Liked by 1 person

  5. Bekki thank you – this is a wonderfully clear precis of how and why and you may even have convinced me to give it a go! My problem is some of my pieces are so big and my home is so small…… I usually revert to a good solid steaming with the iron bit by bit but as nothing is pinned in place until dry it doesn’t have the same effect! Still, I’m bookmarking this post for future reference.

    Liked by 1 person

  6. I used to never block anything and now I block almost everything…even acrylics. That’s because I do it in large part to even out the stitches and it just helps most things look a little more finished. That said, there are some things that shouldn’t be blocked, like pieces knit with a pattern that has significant texture or depth.

    One thing I’ve started doing when washing some pieces is putting a little vinegar in the rinse water. If I have to let something sit in the water for a while, I might put a dye catcher sheet in if I think it might run.

    Have you looked at the before and after blocking thread on ravelry? It’s a wonderful collection of pictures showing the effects of blocking. Worth a look!

    Liked by 1 person

    1. Hi – you’re right it’s horses for course. As I said I’m going to write a follow up tips list and definitely including a bit about care with cables and rib.

      Why do you put the vinegar in? Is it to stop the colour running? And not, I haven’t seen the thread, but I’ll take a look.

      Liked by 1 person

      1. Yes, to stop the dye from running. I Don’t know enough about dyeing to know which circumstances it works in and which not, but some of the yarns I’ve used lately have had it on the ball band as a recommendation. Seems to have worked (or at least not harmed) so far!

        Liked by 1 person

  7. Very interesting post. I usually work with 100% acrylic yarn. I prefer wet blocking it cause that way it gets its first wash at the same time!
    Currently I’m working with a polymide based yarn. Any ideas on how to block that??


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