...Central model of the cube turning inside out. (J.P. Petit 1991, C. TARDY imagery) ...Here we show how this model can be built by making four elements using yellow and green cardstock. A cutting pattern, invented in '91 at the same time as the model, will be given soon. ...For information, the other stages of this cube turning inside out remain to be invented. We will indicate another one very soon (I need to pass the cardstock model on to Christophe so that he can convert it into a new object for the virtual-reality bestiary)