What does blocking mean in knitting & crochet? (step by step guide)

Craft Fix is reader-supported. If you choose to buy via certain links I could earn a small commission at no cost to you more

What does blocking mean?

Blocking is the final stage in a knitting or crochet project where you set the size and shape of your finished object and give it a professional finish. There are 2 main blocking methods: wet blocking and steam blocking. Wet blocking is easier and safer as it mainly involves just washing and drying your project. Find out what you need to wet block your knitting and crochet along with a step by step guide with pictures.

Do you have to block knitting and crochet?

No. It’s only essential to block lace knitting and crochet work. That’s because lacework needs opening out and setting to reveal the lace patterns.

However, most knitting and crochet will benefit from blocking. It can transform messy or uneven stitches into a beautiful piece of work as if by magic. It’s well worth taking the time to block your project to get a professional finish, especially if you have put a lot of hours and effort into making it.

What can you use to block knitting and crochet?

You could go to town buying special blocking equipment, like a blocking board and blocking wires. But that’s not necessary & you can just use items you already have at home instead. Here’s a list of what you need:

  1. A flat surface big enough to lay your finished piece on
  2. Towels (preferably larger than the item)
  3. Cool water
  4. A sink or container large enough for your item
  5. A measuring tape (if size is important)
  6. No rinse wool wash (optional but recommended)
  7. Rustproof pins (optional except for lace projects)
  8. Blocking mats (optional: you can use towels instead)

If you’re blocking a smaller item, an ironing board works well as a flat padded surface. For larger items like sweaters or blankets, you can use towels on a floor or spare bed. I’ve also heard of crafters successfully using thick corrugated cardboard packaging leftover from parcel deliveries as a blocking surface.

interlocking foam blocking mats
8 squares are ideal for blocking sweaters. I only have 6 so cover them with a towel as my sleeve ends are off the mats

I got some affordable interlocking foam blocking mats several years ago that have served me well. My green Crochet Dude ones are no longer available, but I think this 4 pack of Boye blocking mats on Amazon is the same brand & budget friendly. 2 packs gives 8 squares which is ideal for sweaters. I only have 6 squares so I cover them with a towel as my sleeve ends run off a bit.

Blocking mats are often quite expensive, but I got a great tip from a local yarn store to use kids puzzle play mat squares instead (like this 8 pack – you can flip them over to use the smooth side), which are cheaper and more widely available.

Should you block each piece separately before joining them together or block the complete item at the end?

Block blanket squares individually

If you are knitting or crocheting a blanket made out of squares, you should block the individual squares first before you assemble your blanket. They will be easier to join together when they are all the same size and you will get a much better finish too.

You can just pin each square out separately on towels, mats or an ironing board. But if you like crocheting squares, you can get fancy blocking boards for crochet squares, hexagons and other small pieces. This means you can easily stack and block a bunch of squares together which can be a real time saver.

I didn’t know blocking boards existed back when I crocheted a 48 granny square rainbow blanket. I still have flashbacks to pinning each square out individually to block them. I did a few at a time on an ironing board & it took FOREVER!

When to block sweaters knit flat in pieces

If you knit a sweater flat in pieces, you can either block it piece by piece or at the end after seaming.

Knitting reference books usually say to block each individual sweater piece. Vogue Knitting – The Ultimate Knitting Book advises “most pieces of knitting should be blocked before seaming….the only times you would block a completed sweater is when making a circular garment or when washing a sweater after wearing it”.

However, in the real world lots of knitters just wash and block their finished sweater instead. Many modern patterns assume this too.

The advantages of blocking each sweater piece separately are:

  1. It’s easier to seam blocked knitted pieces together and get a neater finish.
  2. If you block the first piece as soon as you finish it, you can check its size and end result & adjust if necessary instead of knitting a whole sweater that doesn’t fit well.
  3. You don’t need as much space to block each piece.

However, blocking each piece takes longer and is a bit of a faff. Plus, you knit the neckline after seaming at the end in some patterns. So if you blocked in pieces, you’ll need to dampen the neck or spray it with water at the end to block that too.

I’ve blocked sweaters both ways, and found it makes no difference to the end result. If I’m worried about fit, I usually knit a sleeve first and block it. If I’m having trouble getting a neat finish joining pieces, I’ll block them to sort that out. But generally I just block the finished sweater at the end & it all works out fine.

How do you wet block knitting or crochet?

Step 1: Put out blocking mats or towels on a flat surface 

You need a flat surface large enough to lay your piece out on. Use a floor or a spare bed for sweaters or large items. An ironing board works well for smaller pieces.
Lay out your blocking mats if you have some. I cover my blocking mats with a towel but this isn’t necessary.
If you don’t have mats, you can just use towels. You may want to put plastic bags or sheeting underneath to keep your surface dry, or you could layer towels instead.

Step 2: Soak your knitting or crochet in cool water for 30 minutes

Fill a sink or a plastic basin or bucket with enough water to completely submerge your piece. I add a couple of drops of Soak no rinse wool wash. It makes my knits lovely and soft.
For small accessories and blanket squares, you can use a smaller container like a bowl or a deep tray.
Put your knitting or crochet in the water and leave it to soak for around half an hour so that the yarn fully relaxes. Do read the washing instructions on your yarn ball band just in case it needs special care or should not be left to soak.
If you’ve used easy care yarn that’s machine washable, you can machine wash your piece instead on a wool or hand wash cycle if you like. I’m not brave enough for that though! Even if I hope to machine wash in the future, I always hand wash the first time to see how that goes. 

Step 3: Take it out and gently squeeze in your hands to remove excess water

Post soak knitting in a heap

Lift your piece out of the water. It will be sopping wet so gently squeeze it to remove the main excess water. Don’t wring it out or anything. Just press the heaped ball shape with both hands and a fair bit of water will come out.

Step 4: Roll your piece up in a thick towel and press it repeatedly

Put your heaped piece on a thick towel. Carefully lengthen it out and then roll the towel up length wise, a bit like a swiss roll cake. Then press down firmly on the towel several times to get more water out. Turn the rolled towel over and repeat. You should see several wet patches on the towel.
Open up the towel. You’ve now got rid of all the excess water, so carefully bring your piece to the flat surface you prepared in step 1.

Step 5: Lay your piece out to dry

Blocked cardigan laid out to dry

Gently lay your knitted or crocheted piece out flat on your blocking mats or towels. If it’s a garment or sizing is important, check the pattern sizing or your own notes so you know what size it should be.
Roughly measure at key points and see how far off you are. Carefully lift and adjust your piece until you are happy with the overall shape and measurements.
Certain yarns change a lot when wet. For example, merino can grow a lot in the wash and the weight of cotton can make it stretch vertically. So initially your piece may be much too long and narrow and need a fair bit of lifting and arranging to get the right shape.
For a sweater, focus on the body and sleeve widths and lengths and the neckline width and shape. Also check that the sleeves match well. 

Step 6: Tweak and pin

Blocking a crochet snowflake with lots of pins

Once you’re happy with the main measurements, take a closer look at the stitches and any patterns or detailing. Smooth out any lumps and bumps and neaten any wonky bits. If you spot any loose stitches, you can use a blunt needle or a small crochet hook to carefully take the excess yarn and spread it out among nearby stitches. 
Take time to open out design features like cables and especially lace work to make them sing. Lace designs will need lots of pinning to open up the lace pattern and get it to dry out in that position.
For other projects, adding a few pins at key points like square corners or down the front of a cardigan is helpful to keep straight lines for a professional finish.

Step 7: Leave until fully dry

Finally, you need to wait until your piece is fully dry, which will take days rather than hours.
Wet blocking takes 1-3 days depending on the yarn material and the drying conditions. Heavy sweaters or blankets, especially those made with cotton, take longest to dry.
Don’t be tempted to move your knitting or crochet before it’s fully dry or you could ruin all your hard work. Even when the top feels dry the bottom may not be.
I do sometimes turn sweaters over after a day or so if I’m confident the top is dry but the other side is still quite damp. This needs to be done slowly and carefully. I gently fold the sleeves in and then the bottom up, so that the sweater is a folded square shape. Then with one hand underneath and the other on top, I turn the square upside down, so the back of the sweater is now on top and carefully unfold it again to finish drying out.

Do you need to block after every wash?

Lace projects do need to be fully blocked after every wash unfortunately. It’s the only way to open up and set the positions of the lace patterns.

But for general knitting and crochet projects, the major blocking work is a one time thing.

Any changes that washing will make to your yarn, e.g. blooming (where the yarn becomes fuller) or growth or shrinkage, should happen on the first wash. So the biggest differences are between your finished item before and after the first wash. There’s no need to go through some big blocking rigmarole every time you wash your hand knits or crochet.

However, like commercial knitwear, knitted and crocheted garments should be dried flat. Since wet blocking basically just involves washing and drying your garment flat, the process is similar after every wash but shorter than the first blocking. 

Every time I wash my handknit sweaters, I either soak or machine wash them depending on the yarn. If they’ve been soaked, I squeeze them in a towel to remove the excess water.

For lighter sweaters that dry quicker, I may just lay them on an airer. Otherwise, I put my blocking mats on the floor covered by a towel and lay my sweater out on top to dry for a day or 2.

But I don’t do any special fixing or pinning on 2nd and subsequent washes, unless it’s a lace project.

If I know a particular sweater tends to go out of shape in the wash, I roughly measure the problem area & give it a quick stretch or pull up so that it dries at the right length. But that’s it. The next day, I’ll quickly turn over heavy sweaters and remove the towel to speed up the drying of the other side, because I don’t need to fuss about setting the final shape the way I would with the first blocking.


I hope this guide has helped you understand what blocking is all about and how to block your knitting and crochet. Wet blocking is really just washing and drying your finished piece to get the professional finish you deserve after all your hard work. It’s well worth doing, so give it a go for your next project and see the magic of blocking for yourself.

Got any questions or blocking tips to share? I’d love to hear from you. Just leave a comment below.

Leave a comment