Ultracor Inc.'s (Livermore, Calif.) UltraFlex honeycomb core features a distinctive cell geometry and, according to the company, can be formed into compound curvatures, without buckling of cell walls. Designed to exhibit mechanical properties similar to those of hexagonal cores of equal density, the product reportedly can be tailored to the customer's use, using almost any nonmetallic material, and core densities can be matched to those of existing hexagonal cores.