I used CAD/CAM & CNC machining to make this ring.

Which is to say, after creating the knotwork design, instead of carving the wax to cast this ring, I used vector graphics software to define my knotwork pattern, and 3D software to define the relief (the high & low parts), and CNC software to control the really cool tiny lathe, and the lathe did the carving, while I spent the eternal hours doing other things, waiting for it to finish.

On the outside. I still had to do the carving on the inside myself. Put a hole through the center, then use extreme precision to enlarge the hole just enough to make the ring both exactly the right finger size and exactly the right thickness, and have the inside-curvature and overall thickness perfectly consistent all the way around the ring.

High-Karat gold is prettier than 14 karat gold. Platinum is prettier than silver, too. Honest.