“SOMETHING THERE IS that doesn’t love a wall,” once wrote the poet Robert Frost —but I was looking for something that does. Namely, a modular, wall-mounted shelving system in aluminum to fill the 10-by-10-foot space in the living room of the new apartment that my girlfriend and I recently moved into. Here was the place where we would finally address our teetering stack of plastic milk crates stuffed with all the books we’d been hauling around for years. They deserved a proper display, their spines upright and facing out. I had a vague idea of something industrial, yet clean. One Google search led to another, and before long, I was staying up late, scrutinizing seductively staged photographs of remarkably flexible shelving systems. The first one that my roving eye fixated on was the String Shelving System, created in 1949 by Swedish designer Nils Strinning. It looks as modern today as it did then, its shelves supported by slender, ladderlike panels made of powder-coated steel; the objects on display look like they’re floating on air. An ever-evolving selection of mix-and-match components—plastic bins, a fold-up desk, a chest of two drawers—allow for customization whether you inst...