Socks That Rock Medium is here! This is our second base from the hand dyer Blue Moon Fiber Arts. Mediumweight is a tightly plied 3-ply sport weight with a similar bounce to the lightweight yarn base that we received a couple of weeks ago. This is a personal favorite of mine. As a “lazy” sock knitter, I like knitting this up on a US#3 for a faster and thicker sock – especially for my husband!