A flat sheet of paper can barely hold its own weight. Fold that same sheet into a series of ridges and it suddenly resists real, standing loads. Flat, the sheet has almost no resistance to bending, it deflects and collapses the moment you apply a load at midspan. Folding it into ridges adds depth to the cross-section without adding a single gram of material, and that depth is what resists bending. Shells get their strength from form, not from material. Fold your own corrugated shell with Mola 4 and feel how much load the exact same sheet of paper can suddenly hold. - @molamodel_