The instructions provide a table of material requirements and sizes for a larger or smaller doily.

22 x 22 inches - No. 50 Mercerized Crochet Cotton, (250 yard ball) 3 balls, No. 12 Steel
25 x 25 inches -No. 30 Mercerized Crochet Cotton (250 yard ball) 4 balls, No. 10 Steel
36 x 36 inches - Mercerized Crochet and Knitting Cotton(250 yard ball) 5 balls, No. 8 Steel