Pyramidal core structure

A pyramidal core structure which comprises:

• (a) two substantially identical panels, each said panel having continuous hollow pyramid shapes embossed in both longitudinal and latitudinal directions to define four-sided embossments projecting from the panels with orthogonal narrow channels between them crossing at intersections, each of the pyramid shapes having slightly beveled edges at all four corners and a slightly truncated top so that one of said panels can be inverted and mated in either of two orthogonal directions with the other of said panels in an appropriate manner to form a core structure;
• and,
• (b) means for integrally bonding said two panels together along mating beveled edges and where a truncated top sits into an intersection of crossing channels, so as to form the core structure into a composite integral structure.