A 3d-printed mold could actually do that. It'd just be a destructive process -- the mold would not survive. Ceramic is cheap enough that this might be okay. R

A 3d-printed mold could actually do that. It'd just be a destructive process -- the mold would not survive. Ceramic is cheap enough that this might be okay. Removal would be a pain. Probably some chemical which melts ceramic but not metal. Perhaps something mechanical which relies on ceramic being brittle to break it up. Dunno.