This is a relatively easy pattern which utilizes spiked/slipped stitch (also called 1-over-3 crossed stitch). The circumference can be increased or decreased in increments of 4 stitches. The sample hat utilized a little over 1/2 skein of Cascade 220 (150 yards) but would have made it a bit longer if I had made for myself. This hat can be worked with any worsted weight yarn but is best if done if a washable yarn.