Crown of cubes
Design : Robert Neale (penultimate units)
Paper : Post-it notes, 144 units (12 per cube)
An old fold from a few years ago, when I experimented with modular polyhedrons.
A classical variation on the penultimate-unit cube where each one is closed inside its neighbor. The process is fairly easy until the last cube : I remember a fun struggle with a toothpick and unwilling units !