(under subclass 194) Subject matter wherein the ribbon is a one-sided surface formed by holding a first end of an elongated rectangle fixed, rotating the opposite end 180 about an axis coincident with a centerline of the rectangle parallel to the long dimension thereof, and securing the opposite end to the first end.
(1) Note. A Mobius strip is a unique topological phenomenon in that an object formed as described above will apparently have two "surfaces", but mathematically and actually will have only one surface. This can be proved by forming a Mobius strip as described and then applying a mark along the surface continuously along the length thereof without lifting the marker from the surface or crossing the edge of the strip. The experimenter will find that the marker will eventually reach the mark initially produced, thus proving
the actuality of only a single surface. In a ribbon*, this permits typing against the apparently two "surfaces" without further manipulation of the ribbon.
