This free pattern will provide you a comfortable infinity sleeve for your Starbucks Plastic 16 oz. Ice Coffee Cup.
This pattern has a 1/2″ seam allowance, but I sew 3/8″ seam for all but the final seam and get a slightly wider/taller fit that measures a little more than the 3.5″ height.
Finished approximate measurements:
11″ top circumference