A sock blank is a long, rectangular piece of knitted fabric created by a knitting machine and then dyed or stamped with color. The edge of the sock blank isn’t bound off — it’s loose so that you can knit from it, pulling the stitches out as you go. The basic idea behind the sock blank is that you’ll get an amazing yet unpredictable colorway when you knit with it. You don’t have to wind the blank into a ball; you just knit right from the yarn end. Sock blanks are most popular for knitting socks, but you can also use them to knit things like mittens.