A product made from an extruded sheet or web of material having a non-linear cross-section, and the process of making the product are provided. The extruded web or extrudate is plastically deformed in selected areas and then folded. When folded into the appropriate shape, the extrudate is formed into a product having a plurality of cells. The cells may have one or more openings, allowing access to an interior of the cell and reducing the weight of the product.

A method of manufacturing a core stiffened structure includes orienting the plurality of core wafers in a non-uniform pattern onto a first face sheet, the non-uniform pattern producing non-uniform spacing between adjacent core wafers; assembling a second face sheet onto the plurality of wafers; and curing an adhesive to create a bond between the plurality of wafers, the first face sheet, and the second face sheet.