Can You Block Polyester Yarn?

Blocking is an important step to take when knitting a new project to make sure the size and shape of your work comes out the way you want it to.

The quality of your work can be greatly elevated by blocking.

However not all material should be blocked the same way, so you need to make sure you are doing it the right way depending on your yarn material.

One common question is whether polyester can be blocked—and it definitely can, if done the right way.

In this tutorial, we will cover the best way to block polyester yarn.

What is Blocking?

In the knitting and crochet world, blocking refers to a process of stretching and shaping a project to ensure that it is the proper size. 

Blocking is usually done when finishing a piece to set it's finished size.

Blocking is also used to even out stitches when finishing an item.

There are several different ways to block an item such as:

  • Wet blocking
  • Steam blocking
  • Spray blocking

Not all yarn material should be blocked in the same way.

The best way to block yarn will depend on the material that it is made of. 

Can You Block Polyester Yarn?

Yes, you can block polyester yarn. But you have to be careful with how it is done.

Synthetic yarn like polyester can be steam blocked but it has to be done carefully.

If you are steam blocking with an iron and it touches your project it will melt, so do not let the iron touch your project.

You should hold it about 1 inch away when a blocking polyester piece. 

How to Block Polyester Yarn

steam blocking

  1. Lay the polyester item that you want to block on a flat dry surface like a towel
  2. Make sure your item is in the proper shape
  3. Take your iron and turn it to a high steam setting
  4. Hold the iron about an inch from your item and slowly begin steaming the item
  5. Make sure that you are keeping the iron about an inch from the fabric. Do not let the iron touch your item
  6. After you have thoroughly steamed your item, allow it to cool and air dry.

After you've blocked your item you can pin it to a blocking board, but this is optional.


Blocking synthetic material like polyester is going to be a little different than blocking other yarn material.

The main thing is that you need to use heat and not allow the iron to touch the fabric. 

Otherwise its a pretty simple process!



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