I'm using Kona white while doing the Craftsy BOM and dang if I can tell which is the right side. Sometimes I can, sometimes I can't. It's hard. The wrong side seems to be whiter and a looser weave, to me. Am I right? It doesn't seem like the weave could be looser on one side, but it looks that way. Maybe I'm explaining it wrong. Maybe I should say that you can see the bare thread laying there...not all woven like it should be. Anyway, my blocks have both side on it. And I work only during the day. And I have good lighting. What's my excuse? I think I get tired of checking. Now I will mark an X on the wrong side BEFORE I cut. Ohhhh, 16 days until a new BOM! Can't wait!!!! I'm all caught up.