Every reflective surface in the archive is the parent metal, polished — never plated, never lacquered. The sequence runs eight grades, from a 120-grit grind that removes casting skin to a final compound pass on unstitched cotton.
Eight is not a mystical number; it is where measurement stopped improving. A ninth grade produced a surface that gauged marginally finer but looked identical at viewing distance and doubled the finishing time on Exochronos. The archive standard was set at the last grade the eye can testify to.
Brass takes the same sequence with a warmer final compound and forgives less: the metal is soft enough that an impatient pass at grade six leaves waves visible at grade eight. On brass editions the sequence is a discipline, not a recipe.
Maintenance position
Owners are given the final two grades as a kit. Nickel-silver may be left alone indefinitely; brass may be renewed or allowed to darken. Both choices are recorded as part of the specimen's service history.