The guys over at, fittingly enough, Pittsburgh Anodizing worked up the anodized aluminum circles for testing. They’re the same guys who anodized one of my prototypes last summer and are, similarly, a class act. On their behalf, I should make a note about the cracking you see in the photo. First, it appears a lot more prominent there than it does in person, and second, it is mostly the result of me flattening the material (I had delivered it to them a bit warped) after it was anodized.
Neither anodizing nor laser etching are cheap, but the reason I like them so much is that they work with, rather than cover over, the underlying material. Anodizing turns the skin of soft aluminum into a super-tough oxide. Laser etching, as it was done here, pulverizes that oxide leaving an indelible mark. Nothing to wear off over time. No waste. Beautiful.