Measurements
Front seam
20, 23 cm
8, 9 in

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

Materials
STUDLEY DOUBLE KNITTING
Sugar Baby
6, 7 20 gram balls
Studleyknit
6, 7 20 gram balls
Five-in-One
2, 2 100 gram balls
Yorkdale
3, 3 50 gram balls
Elastic
Stitch holders.

Yarn amount required for complete set with either Bonnet or Helmet
STUDLEY DOUBLE KNITTING
Sugar Baby
14, 17 20 gram balls
Studleyknit
14, 17 20 gram balls
Five-in-One
3, 4 100 gram balls
Yorkdale
6, 7 50 gram balls