This had is made using 100% wool worsted weight yarn and a 10.00mm crochet hook. I give you all of the instructions on how to felt this hat and how to make it larger or smaller if you prefer. You will need a dryer and a hat form or foam head in order to complete this project. The hat is made very large and then shrunk down to make the stitch come together and get fuzzy. If you have never felted/ fulled a crochet project before then this hat is perfect for you to begin with!!