Abstract: An article cut from a metallic sheet, has a first pattern of struts forming a plurality of inner apexes situated substantially within a plane that contains the plurality of the inner apexes. There is a second pattern of struts forming a plurality of outer apexes that are situated substantially within the plane containing the inner apexes. Each outer apex has at least one strut in common with an adjacent inner apex. There is also described a method of forming a non-planar three dimensional structure by patterning a planar sheet of material to form an article having a plurality of inner apexes, a plurality of outer apexes with a common curvilinear strut between an inner apex and an adjacent outer apex. Thereafter, everting the article into a non-planar three dimensional structure with the inner apexes at one end of the structure and the outer apexes at another end of the structure.