I have the same problem! :mrgreen: But usually if I hold the fabric where I can see both sides at once, one side is a little "sharper" in detail than the other, or has a smidge more color.
If I'm still not sure, I get a second opinion from DH.
And then if neither of us is sure, I just pick a side and go with it. I figure if the two sides are THAT close, nobody will know if it's wrong-side-out anyway. :)
Sometimes I mark or safety-pin the right side of the fabric when I buy it, when it's still folded from the manufacturer. Then it's easy to tell which side is which after it's been washed. Unless the manufacturer put it on the bolt backwards .... Aaaahh! :-o :lol: ;)