Carbon ink comes to mind, although carbon ink can be only applied to surface and vias (no internal layers afaik).
I am not sure how to integrate that in a toolchain (managing libraries, testing, DRC, etc). For termination of GHz signals under FPGA it might have its place but in mainstream electronics the access to this kind of service seems quite limited. For analog applications and 3% tolerance - niche market.
I am waiting for a built-in transistor