(EN) A thin- sheet panel assembly. In one embodiment, a substantially rigid thin-sheet panel assembly (50) having anon-rigid thin-sheet component includes the thin- sheet component (51) which has selected plan area and shape, a backer (60)having a plan shape and area substantially similar to the thin-sheet component, and plural riser elements (64) of selected heightand configuration each extending from the backer to distal ends connected to a reverse surface of the thin -sheet component, theriser elements being configured and disposed in an array which causes the assembly to have substantial rigidity in a selected directionin the thin- sheet component, and the thin- sheet panel assembly further includes a bar (78) coupled to the backer and extendingbetween at least one pair of adjacent riser elements of the plural riser elements.