This can be made with any fingering weight yarn, however natural fibers (picture on pattern is made with 100% silk noil) and picture here shows it made with a combination yarn of merino wool, superfine baby alpaca and nylon.
Blocking really makes this scarf POP. I spray finished item with water with some lavender oil in it, and you can lay it across you bed on towels (I use foam blocking boards, but it's not necessary) and pin using stainless steel pins. I turn my ceiling fan on and within a few hours, it's dry.
9 double crochet=2"
430 yards fingering weight yarn (best to use natural fiber), 3.75 mm hook, tapestry needle