Engrave the line before the fill
Every cityscape and cartouche is cut into the silver first; the alloy only follows the burin.
A blue-black, never an ink-black
Fused at heat, the chern settles to a cool grey-black with a faint shift toward blue.
Burnish until the relief reads
Polishing the field lifts the silver highlights and sinks the niello into its recesses.
Bound by metal, not by colour
Nothing strays past the silver-to-niello range; the whole plaque stays a single monochrome.