We first saw this origami on an origami website written by Wonko and thought you’d like it! Not for the feint hearted and not easy to make however it is very effective.
Now the “purists” amongst you will recognise this as a “Concertina”, but that is splitting hairs, given a “Bandonéon” is square, this is clearly hexagonal. However its Very Cool!
Unlike the original, the design is based on a 32 x 20 grid, making an extra gather in the bellows section (which is not a bad thing) and a simpler join along the long seam (which, sadly, needed to use double-sided tape to close).
The geometry of this model is really nice – the bellows almost fold themselves when the creases are laid in – Joisel experimented with the seam in and thought it looked better with the strappy seams out in the bellows.
Fashioning handles at the end happens quite naturally if you have been neat, and folding it without any extra creases is possible if you concentrate, making the presentation fold very tidy indeed.