Just What is Blocking?
Types of Blocking
In wet blocking you take the fabric, submerge it in water and leave it to soak anywhere from 30 minutes to overnight so the fibers become full saturated with water. Once the item has soaked long enough the fabric is then removed from the water and either rolled in a towel to remove the excess water or put in the washing machine for a quick zip through the spin cycle. If you choose the washer option PLEASE make sure it is only for a spin cycle. This is just to get the excess water out. The item is then put on an appropriate form such as a sock blocker for socks of pinned to blocking mats to the desired size, shape or openness. Allow to air dry and the garment will retain the desired shape until you wash it and the process of blocking will need to be repeat again.
In steam blocking we use, you guessed it steam. For steam blocking you can use a garment steamer the steam function of your iron. Regardless of using the steamer or iron DO NOT under any circumstances put the iron or the head of the steamer unit in contact with the fabric. Keep either several inches away from the fabric and allow the steam to saturate the fabric until it is damp. This will allow the fibers to become relaxed and absorb some moisture so when they dry they will retain the new shape/dimensions. Once the item is appropriately saturated with steam you can then pin it out to the desired size/shape. Allow to air dry and the garment will retain the desired shape until you wash it and the process of blocking will need to be repeat again.
In either types of blocking pinning the item takes the most time. You can choose not to pin the fabric however I find the results are not as strong as when you take the time to pin out your fabric. The pins force the fabric to retain the final shape in stronger fashion than they do when pinning does not happen.