Abstract: A contiguous planar composite sheet-like structure includes a pair of outwardly facing laminar thermoplastic sheets having generally planar outwardly and oppositely facing surfaces and a honeycomb inner core having axially elongated honeycomb cells with cell axes substantially perpendicular to the outwardly facing thermoplastic sheets, with the honeycomb inner core protruding into the laminar thermoplastic sheets sufficiently far that the honeycomb cells are securely retained by the thermoplastic sheets. A method for manufacturing the composite sheet-like structure encompasses heating either or both the thermoplastic and the honeycomb inner core and thereafter pressing these members together to effectuate the desired composite structure.