Two by One
This pattern is for a completely corrugated ribbed hat. This hat is perfect for leftover balls of worsted weight yarn and is a great way to get a handle on knitting with two colors.
Finished sizes included in pattern:
18" (20", 22") [46, 50, 56 cm] to fit child (medium adult, large adult).
For more info, see Zigzag-Stitch.