Measurements
Cap round head
38, 42, 46, 51 cm
15, 16½, 18, 20 ins

Each pattern has a different set of recommended yarns. The following are from the Studley version.

Materials
STUDLEY DOUBLE KNITTINGS
Tricel/Nylon Crepe, Supreme, Superwash (machine washable), Serenade, Super Pure New Wool, Studleyknit, Petspun or Swiss Nylon
Main: 3, 3, 3, 4 balls
Contrast: 1, 1, 1, 1 ball
Stitch holders.