Measurements
To fit average head

Each pamphlet has a different set of recommended yarns. The following are from the Midgley and Catton version.

Materials
DOUBLE KNITTING
Tulip Tricel/Nylon Double Crepe, Tulip Triacetate/Nylon Double Knitting, Mascot Courtelle/Nylon Double Knitting, and Homestead Double Knitting with Nylon
3 balls.