Small is knitted on a size 6 knitting needle.
Medium is on a size 8 knitting needle.
Large is on a size 10 knitting needle.

Sweater takes about 16 ounces of main color and 2 ounces each of five assorted colors knitting worsted weight yarn, one pair standard knitting needles number 5, crochet hook size F and 11 buttons.

Gauge:
Small: 5 sts equal 1 inch on number 6 needles
Med: 9 sts equal 2 inches on number 8 needles
Large: 4 sts equal 1 inch on number 10 needles.