You didn't put them on acid !
It was Lopp who has done the test, not Willi.
And it was put into acid, actually. As you can see, one of the points was the corrosion test. And, if you look up for the methodology, the corrosion test means keeping the plate in acid for 12 hours:
Corrosion
The device is submerged in a bucket of 16% muriatic acid and left for 12 hours or until bubbling ceases. Are strong acids a threat vector you should be worried about? Probably not, but these tests are extreme in order to see which devices stand out from the pack!
The more different tests are carried out with the Recovery Seed Plate, the more complete information about the capabilities of this storage medium can be obtained, which allows taking into account the resistance to external influences during storage of this plate. Of course, this is good, but the acid test seems exotic to me, because acid is extremely rare in domestic conditions, not to mention that somehow it gets on the seed plate. Hypothetically, such a possibility exists, but with a very small chance. A piece of metal is still a piece of metal (of course, stainless steel) and it takes a lot of time to destroy the text from the surface. So, don't worry about the acid test.
