Hospitals have a continuing need for hats for newborns and cancer patients of all ages. In general, these hats should: Be made of natural materials. Be machine wash- and dryer-safe. Include a brim or other shaping to distract from the lack of hair. Be soft and beautiful. The Ripple Brim Chemo Cap meets all of the above criteria, plus it is fun and quick to knit. As an added bonus, the cotton yarn makes it hypo-allergenic and appropriate for summer climates. Hat is sized for Adult S (20in/50cm head circumference), Adult M, Adult L. Each size is approximately 2in/5cm larger in circumference and 1in/2.5cm taller. This chemo cap is written for a DK weight at approximately 6 stitches per inch gauge. There are additional instructions for knitters using 5spi and 4spi. BASIC SKILLS NECESSARY Knitting in the round GAUGE 24 stitches and 35 rows = 4 inches in stockinette stitch (in the round) SIZING / FINISHED MEASUREMENTS Adult S (20in/50cm head circumference), Adult M, Adult L. Each size is approximately 2in/5cm larger in circumference and 1in/2.5cm taller.