Abstract: Readily installable, highly efficient insulating structures for affixation to bodies requiring insulation comprise successive sheets of closely spaced heat resistive metal foil configured to maintain the intersheet spacing under the stress of gravity and other external forces. Each sheet of foil includes a plurality of corrugations which extend through part but not all of the gaps between adjacent sheets to minimize convection, and which in one embodiment abut corrugations of adjacent sheets to maintain the intersheet spacing. In one embodiment the corrugations are V-shaped in cross section and extend along the length of the sheet on one side thereof.