The edge must be there, it MUST. It's not suddenly a continuous loop, there has to be an end. So you run your fingernail around the surface to try to feel it, but you don't feel it. So, you try again, more slowly. Still no. So, you go out in the kitchen turn on the bright lights hold the roll up to the light and try again, much more slowly, looking carefully. Still no edge. So, you grab the x-acto knife out of the pencil holder and cut a new edge, knowing you'll now have two or three layers that are just short pieces, but at least you have the edge now. And, you vow, that this time, THIS TIME, you WILL fold the edge over when you're done, the way dad showed you so many times. And you do. Once. But, the next time you use the tape, you forget to do it, so the edge melds into the surface of the tape, and disappears like some devilish magic trick.