For a doily approximately 22 inches in diameter:

• The Famous “Puritan” Mercerized Crochet Cotton, Article 40: 3 balls white
• Steel crochet hook No. 7

For a doily 16 inches in diameter:

• “Gem” Mercerized Crochet Cotton, Article 35, size 30, 2 balls White
• Steel crochet hook No. 12

Listed as 28” diameter in American School of Needlework #1094. Uses 675 yards of size 10 with a size 7 steel hook.