A vehicle seat transitional composite with a structural reinforcement member adapted to be mounted within a vehicle seat to provide support to an occupant. The structural reinforcement member has at least two edge regions and an inner region at least partially bound within the at least two edge regions. The at least two edge regions have a plurality of keying apertures. A compliant layer is adjacent to the structural reinforcement member and has a plurality of projections sized to be received within the plurality of keying apertures of the structural reinforcement member for minimizing lateral movement of the compliant layer relative to the structural reinforcement member.