What we refer to as “printed circuits”—the well-known figurative and literal foundation of most electronic products—aren’t really printed at all, except in special cases. Instead, they’re fabricated by techniques such as chemical etching, additive deposition, laser etching, and even nanostamping. As printed-circuit-board (PCB) line width and spacing shrink, or ever-smaller 3D nanostructures are needed, these techniques are reaching limits. They have become increasingly challenging and costly as even the tiniest of imperfections and roughness can affect functionality and performance.