Blocking is the first step in finishing your projects. Pressing is to sewing, what blocking is to knitting. Once you start blocking your knitted pieces, you can’t imagine not doing it.
Blocking is the process of wetting or steaming knitted 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 and only works for natural fibers. The best way to see how a fiber reacts to blocking is to experiment with the swatch. I always block the swatch prior to measuring the gauge.
Synthetic yarns are heat sensitive and should not be pressed, and wet blocking doesn’t change the nature of the knitted piece due to low absorption of water. Novelty yarns such as lurex (metallic fiber) should not be blocked. Long haired yarns such as mohair and angora, and highly textured stitch patterns become matted or flattened when pressed, therefore, wet blocking is the preferred method. Ribbed borders should not be blocked, as these areas are meant to be elastic. Colorfastness or dye bleeding may be a concern, and is another reason to block the swatch, particularly with high contrast yarns.
Wool fibers and specialty hair fibers respond the best to blocking because of their high resiliency and water absorption. These yarn properties allow the blocking process to “change” or “shape” the pieces for an even surface. I prefer wet blocking; spraying the pinned pieces with water. 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 knitting and inside seams.
A flat padded surface is required for blocking. You can make your own board or purchase one. To make your own, pad a soft fiber board (a decent size is 36 inches square) with heavy batting. Wrap the batting with a fabric such as gingham, and staple to the back of the board. The squares of the gingham fabric can be used as a guide for measuring and pinning.
I block each piece as it is finished by pinning the dry piece right side up to the board with T-pins. For garment pieces, I usually begin by pinning the bust/chest measurement and work up to the shoulders, then to the bottom edge. Use the schematic measurements as a guide for pinning pieces. Space the pins no more than one inch apart, and smooth the piece as you pin. Do not pin ribbed areas, unless the whole piece is ribbed. Your edges should be even, not scalloped. Also, pin according to the shape of the piece, allowing for curves. If your gauge is accurate, you should not have to stretch the knitted piece very much. When finished pinning, spray the piece with water, and let dry completely. After the pins are removed, the piece will lie flat and have an even surface. With small items like hats, scarves, mitts, and socks, I finish the piece, hand wash, and lay flat to dry without pinning out as described above.
Try blocking, particularly before seaming your pieces, and you will surly notice a difference.