> Kevin Beeden concluded, in light of Chris Lucas's results, that, when making cuben articles, it is important to ensure that "all edges are folded and bonded to ensure no micro-tears are exposed to propagate catastrophic larger tears."
I should point out that I've never worked with Cuben, but I am reasonably familiar with a range of materials, including films. It was this experience, and the result of the practical testing that made me make the suggestion about hemming the edges to prevent propagation of microtears.
I've not looked at a cut edge of Cuben, so my microtears comment is, again, based on previous experience with thin films.
Having said all that, I'm still fairly confident that this hypothesis is the explanation for the apparently premature failures that Chris originally found.
My gut feeling is that a small hem should be adequate (say 1cm). A larger hem may even cause trouble on a curved edge, as the cut edge would have to stretch, or be cut to stop the whole thing puckering. And putting deliberate cuts in would seem to go against the whole idea of why you're hemming...