Abstract: A first panel is hinged to a second panel by first, second, and third straps, which are flexible. Each strap is secured to the first panel, near a first end of such strap, and to the second panel, near a second end of such strap. Each strap passes through a slot of the first panel, partly around an edge portion of the first panel, partly around an edge portion of the second panel, and through a slot in the second panel. The first and second straps pass in generally opposite directions between the edge portions of the first and second panels so as to appear to cross each other when viewed along the edge portions thereof. The second and third straps pass in generally opposite directions between the edge portions of the first and second panels so as to appear to cross each other when viewed along the edge portions thereof.