Regarding your tagline — it is not a matter of slicing, but of rotating the end and joining it into a loop. This is then called a Moebius strip and has only a single surface, and a single edge.
That’s cool, Bob!! Thanks! I knew I could get you to show up if I were tricksey enough! ;o]
Wow. I never heard of such a thing. But if you say it’s a thing, then it has be right. Thanks again!