Start-up Forte3D’s carbon-fiber 3D printed cellos and violins follow a familiar pattern in 3D printing innovation: someone needs something faster, cheaper, or more efficiently than traditional methods, so they turn to 3D printing. Then someone else refines that idea, perfects it, and builds a business around it. Forte3D isn’t the first to produce 3D printed string instruments, but it may well be the best-sounding.