In knitting, crochet and other handmade textile arts, blocking is a final stage of handmade textile production that adjusts the shape and size of the finished piece. Not all pieces need blocking; however, blocking is standard for lace work and is not uncommon in sweaters, socks, and other solid projects. Through heat and moisture, blocking sets the stitches and standardizes the final dimensions, and may enhance the drape.[1] [2] Hand manufacture places natural stresses on fabrics that may result in deviations from its intended shape and size. Blocking is only effective on natural fibres[3] but a technique called killing may be used on synthetic fibres to achieve an effect similar to blocking.
The degree of malleability is determined by the type of yarn used, with wool providing the most flexibility. For projects that are produced in sections or piecework, blocking is normally done prior to final assembly, and may be repeated after final construction.