Milan-based product designer Alessandra Galli has designed Enne, a light-duty ladder that practically disappears when folded up.
If it's not obvious from the cut-outs in one of the rails, it's made with a minimum amount of materials. "As for the manufacturing process," Galli writes, "the steps were [cut out] from one of the two side pillars, thus optimizing the material and allowing the object to close completely on itself."
While I wouldn't want to climb it with heavy items or tools, it would certainly be convenient for occasional use in a space-tight environment.
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