A support member is useful for supporting membranes such as solid polymer electrolyte ion exchange membranes such as those used in electrochemical cell applications. The support member has a first lattice pattern on a first side of a single piece of material. A second lattice pattern on a second side of the single piece of material cooperates with the first lattice pattern to establish a plurality of flow passages across the material. Each lattice pattern has a corresponding plurality of recesses that extend partway through the material and overlapping portions of the recesses define the flow passages. In a disclosed example, the monolithic support member lattice patterns are established using chemical etching.