I don't know if any one else has read this but when I started making pillowcases for my grandkids, I read to use this formula 9 x 3 = 27, 9" for the wide band and 3" for the smaller band and 27" for the actual pillowcase, I have always used this way and I have made dozens of pillowcases over the years. I love making them and the grandkids love getting them. I have a grandson who just moved in his first apartment after college, and I made him quite a few.