How to: Block A Sweater
After you have invested a great deal of time into knitting a sweater, you want to give it a beautiful finish. This often involves blocking the sweater to the proper dimensions. When you block a sweater, you are setting the stitches and evening out the fabric in addition to preserving the correct sizing. Generally, sweaters can be wet blocked (good for cotton and linen), spray blocked (good for wool and alpaca) or steam blocked (good for wool and alpaca) depending on their fiber content.
If your garment is going to be pieced together, you should block the pieces before sewing them up. This will help you to line up seams and to even out the garment to make the joining easier.
After subsequent wearing of the sweater, wash the garment as the yarn label indicates. To recreate dimensions that may have been lost during laundering, reshape the washed garment and dry flat.
Note: You should always consult the washing instructions for your yarn before blocking or washing your sweater. It is also a good idea to test your blocking method on your gauge swatch to see the results before you begin on your final project. Blocking works well on animal fibers and cotton, but is often unnecessary with synthetic yarns.
Recommended for wool and animal fibers in general, wet blocking involves fully wetting your finished pieces.
First, fill a clean sink or basin with water. For water temperature and soaking time, follow the yarn label's recommendations for the yarn used. Generally, we recommend using lukewarm water (hot water may cause felting in wool!). If using, add wool wash to the bath and swish to distribute evenly.
To soak, gently submerge your project, gently squeezing out any air bubbles so that the piece is fully saturated. Never place any animal fiber items under running water as this agitation may felt your fabric.
Allow the piece to rest in the bath for at least 10 minutes and up to 30 minutes. To remove your project, gently lift it out of the water, making sure to support its weight evenly so that the fabric doesn’t stretch and distort under the extra water weight. Gently squeeze (never wring!) to remove excess water.
Next, lay your project flat on a clean, dry towel.
Roll your project up in a single layer or fold into thirds to make the rolling size more manageable. Press gently and evenly on the rolled towel to remove excess moisture before unrolling and laying your garment flat to completely dry.
To block a garment or project to specific dimensions, lay your project on blocking mats or another pinneable surface. Gently adjust your garment until the piece matches the pattern’s finished measurements or schematic dimensions. Use T-pins when necessary to maintain precise dimensions during the drying process.
To spray block your sweater, you will shape the garment or pieces first and then wet them.
Stretch your items out and pin them to the correct dimensions on a blocking board or other colorfast, absorbent surface. (You can use several towels layered over one another to create an appropriate blocking surface.)
Once the sweater is secured in the shape that you want, use a spray bottle to evenly dampen the surface and allow to dry completely before you remove the pins. If you don’t have a spray bottle, you may also lay damp cloths or towels on the sweater to achieve the same results.
To steam block a garment, you will prepare it just as you would for spray blocking above.
After the item is pinned into place, pass an iron (on the steam setting) or a steamer over the fabric, holding it about an inch above the knitting itself. You don’t want to touch the steamer or iron directly to the fabric because it could flatten the stitches or create an undesirable sheen. If you are worried about touching the knitting with the steamer, you can place a thin towel or sheet between the heat and the sweater.