Superwash wool is wool that has been treated with either acid or resin to prevent it from felting. Felting occurs when the scales of untreated wool bind together as a result of agitation and heat, shrinking the finished object considerably and obscuring stitch definition. Knitters and crocheters who love the feel of animal fibers but want a machine-washable item often choose superwash wool for their projects. Superwash wool is stretchier than untreated wool, making it ideal for blocking into shape.
Spread a large towel over a surface into which you can stick pins, such as a bed, ironing board or carpet. Lay the superwash wool item on the towel.
Insert straight T-pins all the way around the edge of the item, stretching it into shape as you go. Use one rust-proof T-pin every 2 inches; more if you are blocking a lace shawl or scarf with sculpted edges.
Fill a steam iron with distilled water. Allow the iron to heat on the steam setting.
Hold the iron 2 inches above the pinned item. Press the steam button and hover the iron over your knitting or crochet until the yarn becomes damp.
Allow your work to dry before unpinning it.
Do not use straight pins with plastic ends, as the ends can melt during steam blocking. Do not touch the iron to the wool.