This pattern is written to knit in worsted, chunky, or in super bulky yarns, so you will need to select a needle to give you tight gauge depending on the yarn you select and your knitting style. The top will tend to be puffy, due to the unraveled stitches, so your fit focus is the ribbing on the band of the hat. This pattern also works best with wool and wool blends - slippery acrylics, bamboo, and cotton will not produce the same stitch definition as wool, but are still usable if knit tightly.