I used to order white Cotton Concealers from Underworks. I felt that the sizes were consistent, but the sizing chart (at least back then) was not fully accurate and caused me to order a too-large binder the first time. It worked, but not as well as the next size down. Unfortunately, I was losing weight at the time, too, so the large binder became pretty ineffectual pretty quickly--that is, because of the weight loss combined with the largish binder combined with the inevitable stretching. But the next size down was great.