A heat exchange cell for a recuperator includes top and bottom plates sandwiching a matrix finned member and a pair of header finned members. The top and bottom plates each include a pair of manifold openings, and the header finned members each include a curved free edge following the curvature of an associated manifold opening. The header finned member includes a high fin density portion along the free edge and a low fin density portion communicating with the high fin density portion. The dual fin density header finned member thus provides increased structural strength along the free edge and provides a low pressure drop through the low fin density portion.