Klein bottle by sarah-marie belcastro

Klein bottle

This pattern is available for free.

This is really a recipe rather than a pattern---you get to decide on your yarn, needles, and gauge. The number of stitches you cast on determines the length of the central Mobius band of the finished object, and the number of rows you knit determines the circumference of the orientable homotopy generator (sorry, I can’t think of a clear plain-speak way of saying that---muddily, it’s “the other circumference”).