Steam blocking is the third and most notorious method of all blocking methods (see related articles). I say notorious, because there are quite some things you need to take into consideration when using this blocking method.
First of all, it’s aggressive. Steam is hot and will treat your yarn harshly. So don’t use this method for delicate yarns such as Silk. However, if you have stubborn fibers such as cotton and acrylic this method might benefit your work. Secondly, you have to be careful with your steam iron. If you use any of those colour-covered headpins, and you touch it with your steam iron, they will melt, with a bit of bad luck onto your piece. It’s not pretty and impossible to remove. Thirdly, steam blocking is usually not recommended for acrylic, as acrylic fibers can melt. The fact that they melt can be used to your advantage though, a process known as ‘killing’ your fiber by melting small parts of the fiber. However it’s irreversible and therefore pretty tricky to get right, considering you only have one shot.
Generally speaking you can safely use this method for cotton fibers. Cotton is a pretty durable fiber, and I use this method to make my potholders nice and flat. Same goes for pieces that crease a lot, such as cotton placemats. Just be very gentle with your steam settings.
- A steam iron
- Blocking mats (available on Habbedash and Woolwarehouse).
- T-pins. I’d definitely choose T-pins over regular pins. They’re sturdier and easier to place. Whatever you choose, make sure they’re made out of stainless steel (available on Woolwarehouse and on Loveknitting (US))
- Eucalan, a leave-in yarn detergent. Technically not necessary but I would heavily recommend it! (Available on Habbedash and Woolwarehouse)
Nice to have:
- Blocking wires (available at Habbedash)
- Blocking boards (available on Woolwarehouse)
- Sock blockers, the name says it all. They’re to easily block your socks in shape. They are available in multiple sizes. (on Woolwarehouse)
Steam blocking tutorial
1. Pin your item into shape on your ironing board or blocking mats. If you have picots or shells in your pattern, pay extra attention to them to really open the pattern up. You may stretch your piece a little, but make sure not to form any peaks by overstretching your yarn.
2. Set your steam iron to its continuous steam output and hover over your piece, making sure not to touch the pins. Always keep a distance between your piece and the iron, around 3-5 cm or just hover above the pins. If you can’t reach certain spots, lift your iron a bit higher and give it a small steam burst. Hover over it for 30 seconds or so, and carefully feel your work. It should be hot, but not scorching hot (if so, you’re too close!). If it feels like it’s not resisting the pinned shape anymore (for example, the above example first really wanted to go back to its concave shape but after blocking it was perfectly flat) you’re done. If not, block for another 30 seconds. After that, it should be done. If not, it’s probably never going to be in the shape you pinned it. Put your iron away.
Don’t touch the pins right away: they’re going to be pretty hot. Something that goes for acrylic only: you will notice when you’re coming too close to your acrylic, because you can see it ‘wilting’ away a little bit (melting). If this happens, immediately stop.
3. Leave your item to cool off for around 30 minutes. Afterwards, unpin.
(The pattern used in this example is the Roller coaster.)