SteelKi is available on Amazon. It doesn’t appear to make any durability claims.
Setup
Extremely straightforward; it only takes a few minutes to engrave the words by hand. They’re highly legible due to the black varnish that covers the plate.
Heat Stress Test
The black coating didn’t even last 30 seconds under the flame; don’t rely upon it for high visibility after a fire. It’s hard to see from the photos but the etching is still slightly visible at the right angles - no data loss, but not great. I’m less confident in this hand etching than in the electrochemical etching or stamping methods.
Corrosion Stress Test
It seems like the words are MORE visible now…
Crush Stress Test
Bent but no data loss.