A porous structure having a plurality of bonded sheets each sheet having at least one aperture that partially overlaps an aperture of at least one other sheet. A method of producing a porous structure including stacking a plurality of sheets each sheet having a multiplicity of apertures, and bonding each sheet to its adjoining sheet. An open-pore network structure having a multiplicity of sheets each having a repeatable pattern. At least a portion of each sheet is bonded to the web of an adjacent sheet. The porous area of at least one of the sheets is askew to the porous area of at least another of the sheets. An open-pore structure having a multiplicity of bonded sheets, each sheet having a repeatable pattern defining a multiplicity of perforations, and a plurality of apertures defined by the repeatable pattern, the apertures extending through the perforations of at least two adjacent plates.