Materials, components, assemblies, and methods consistent with the disclosure are directed to the fabrication and use of sheets of material to provide channels for cooling through the flow of gas. An assembly for cooling can include a stack of alternating first and second blades, where each blade exhibits at least a first edge, a beveled edge, and a bend, the bend defining at least a first region and a second region, where the first region is substantially flat and bordered by the edge, the beveled edge, and the bend. An assembly can also include a sheet with folds to provide channels.