2 ms·

In fact, I believe that the article is describing a reinvention of this technique! Just with a plotter on oil rather than a compass on plastic.

• Sardtok 2mo ago
  He did it on plastic CD cases, not oil. The oil in the beginning of the article was just for explaining the refraction that happens with the ridges in the structure.
  • bradrn 2mo ago
    Ah, whoops, thanks!