Stainless steel is an option. It does still corrode long-term[1]. It works fine over decade-to-century timescales for structural applications[2]; I don’t know if we can trust it to retain fine details[3] over long timescales[4].
Laser etched glass is interesting, though brittle.
Said corrosion is slow, especially in proper conditions (in still dry air, no other metals around for galvanic corrosion, etc); it is not, and cannot be, non-existent.
The longest study I found on atmospheric exposure of stainless steel was 10 years. Somewhat surprising considering that stainless steel has been around for ~180y at this point (1840s or so).
Stainless steel is not that expensive, and pretty corrosion resistant. Although laser etched glass may be a better option.
Stainless steel is an option. It does still corrode long-term[1]. It works fine over decade-to-century timescales for structural applications[2]; I don’t know if we can trust it to retain fine details[3] over long timescales[4].
Laser etched glass is interesting, though brittle.
Said corrosion is slow, especially in proper conditions (in still dry air, no other metals around for galvanic corrosion, etc); it is not, and cannot be, non-existent.
...most of the time. Salt water destroys everything.
1mm of corrosion in a 2cm-deep structural member is far less of a problem than 1mm of corrosion on 0.1mm-deep lettering.
The longest study I found on atmospheric exposure of stainless steel was 10 years. Somewhat surprising considering that stainless steel has been around for ~180y at this point (1840s or so).