Adhesive Technologies offers a full range of  structural core materials ranging from PVC  through SAN to End Grain Balsa core.
These Foam and Balsa Cores in a sandwich construction are commonly specified by designers and architects to increase stiffness and reduce the weight/cost of a composite structure.
These cores are available as plain sheets or a variety of forms including Contour Scrim/Vacuum Infusion prep/single and double cut etc.