Cruising Fakebook, as one does, I came across a fascinating origami geometric mindf*ck:

Edu Solano Lumbreras kindly shared instructions for his design, having adapted the techniques used in Thoki Yenn’s “Umulus Rectangulum” corners, to make this tesseract like cubic möbius strip.

Comprised of 6 modules, with some exacting pre-creasing that lends itself to template work, you fold bent square tubes with 3 corners – the shortest corner makes the “tab”, the opposite end becomes the “pocket”.

Folding in a4, the geometry is just as elegant, if exacting.

You make it in 2 mirrored halves, then join to make something that does your head in the more you look at it.

I love this, a lot. Folded from A3 sheets (and possible from A4 also I suspect (must try), based on long 16ths initially, there is a complex geometric construction sequence necessary to determine the landmarks of the corners, then some simple box pleating to have the paper in each corner eat itself tidily.