A process of making a multi-layered product from an extruded sheet or web of material (42) having parallel upper and lower walls (130) and a plurality of spacers (134) extending between the upper and lower walls (130) is provided. Portions of the extruded web or extrudate (42) are removed in selected areas. The lightened web is then folded. Outer skins are then applied to the folded web. The extrudate (42) is formed into a product (10) having a plurality of cells (14). The cells (14) may have one or more openings (34), allowing access to an interior of the cell (14) and reducing the weight of the product (10).