My daughter wanted an earband that would be warm, thin, not itchy, and above all, very cool. This design met her requirements. Soft Swish Yarn or Wool of the Andes Yarn, Knit on smaller than usual needles for a tight fabric and seed stitch edges to allow it to lie flat. Three lengths SM (MED, LG). If in doubt, and the intended wearer is not there to be measured, MED is the best bet!
Finished length before grafting = 18 ( 19, 20 ) in.
This pattern is written out.