[kuschku]

> doesn't it rely on relatively expensive fixed masks prepared for each layer

If you need perfectly sharp edges and high precision, sure. But I'm sure in this case that'd be unnecessary.

> Assuming that doing the process you describe is sufficient, what's the ballpark of what "for cheap" means for you if you needed to print 1000 different fake tags, assuming many layers of "the desired pattern" to print the metal flakes?

I described in another comment an additional way to quantize the layers to reduce the repetition steps, which would reduce costs further.

Regarding costs, you could fake a THzID chip for about 500€ per fake. Not cheap enough to do it for household items, but if you're faking designer bags, clothing, sneakers, or electronics, it'd be absolutely worth it.