Note: the crown is crocheted with two strands of yarn, the brim is crocheted with 1 strand of yarn.
You can use any sport weight yarn that would work up to gauge of 18 sc = 4 inches with two strands held together.

You can crochet a cap with cotton yarn and you’ll have a wonderful cap for the summer.

You can crochet cap for men, using other colors of yarn.