How do you find the right and wrong sides of quilling paper?
And after all the microscopic investigation, I'd like to ask you, “Does it matter?”
My answer would be, “Only if it bothers you.”
If you can’t see or feel it, then I would suggest you don’t worry about it. Most non-quillers are too busy enjoying the overall quilling piece. Besides, when you quill an S-scroll, you’re faced with both a right and wrong side, and there’s not much you can do about that.