Puzzle pieces are not only a fun design, but are also used as the logo for Autism Awareness. Stranded color-work and slip stitches create the puzzle piece pattern on the legs. This pattern includes extensive advice for successfully knitting with two colors in your sock. Puzzle Pieces Socks are knit cuff-down to the toe and feature the traditional heel flap and gusset construction method. Directions are given both in charts as well as line-by-line written instructions.