I’ve professed the benefits of blocking in previous posts and this phrase “yarn + water = magic” is apropos. Yarn really does come to life in water, and will reveal its good and bad properties. Blocking your gauge swatch helps to determine the appropriateness of the yarn for a project, and also makes it easier to measure the gauge. Blocking is really the first step in finishing your projects.
Blocking is the process of wetting or steaming knit pieces to even stitches and fibers, and flatten the edges. Some pattern instructions inaccurately describe stretching the pieces to the correct size. If you have not obtained an accurate gauge, no amount of stretching will change its size, and may damage the knitting. For the best results and easier seaming, blocking should be done prior to sewing. The best way to see how a fiber reacts to blocking is to experiment with the swatch. I always block a swatch prior to measuring the gauge.
Wool fibers and specialty hair fibers, as well as most natural fibers respond best to blocking because of their high water absorption. Synthetic yarns are heat sensitive and should not be pressed. Wet blocking doesn’t change the nature of a synthetic fiber because it doesn’t absorb water, but blends of natural and synthetic fibers can still benefit from blocking. Novelty yarns such as lurex (metallic fiber) should not be blocked. Long haired yarns such as mohair and angora, and highly textured stitch patterns like cables become matted or flattened when pressed, so wet blocking is the preferred method. Colorfastness or dye bleeding may be a concern, and is another reason to block the swatch, particularly with high contrast yarns.
I prefer wet blocking by spraying the pinned pieces with water; the safest approach. I’m not a fan of pressing with steam, as it flattens the knitting and may damage the piece. If you must, press with steam and a pressing cloth, and do not touch the fabric surface with the iron. Pressing works best on stockinette stitch fabric and inside seams.
For garment pieces, start by smoothing out the pieces right side up on a blocking board or on a flat, padded surface. Use the schematic measurements as a guide. Place a tape measure across the key areas, like the bust/chest or the underarm of a sleeve, then put T-pins at each side edge to mark the measurement at these points. Place pins at intervals as you work from these marked points: the armhole up to the shoulders then to the lower edge; from the underarm of sleeve up along the cap then to the lower edge. Also check the length measurements as you pin. If your gauge is correct, the pieces should be the same measurements as in the schematics. Space the pins no more than one inch apart, and smooth the piece from the center out. Your edges should be even, not scalloped. Don’t pin ribbed areas that are intended to pull in or remain elastic. Pin according to the shape of the piece, allowing for curves. If your gauge is accurate, you should not have to stretch the piece very much. When finished pinning, spray the piece with water, and let it dry completely. After the pins are removed, the piece will lie flat and have an even surface.
With items like hats, scarves, mitts, and socks, I hand wash the completed project, and lay it flat to dry without pinning. There are special blockers available for drying socks, and blocking wire sets for lace projects that are difficult to pin out fully.
Blocking really is magic, and will make all the difference in the world to the quality of your projects.