Moiré

two patterns disagree. that’s the art.

slide a printed sheet over another and a third pattern appears; tap for rings, lines, dots or a spiral

Two sheets of fine lines, one over the other, make broad bands that neither sheet carries: they appear only where the two disagree. Slide the top sheet a little and the bands sweep a long way, because moiré magnifies a small shift. Line the two marks up and the third pattern is gone. Tap for rings, lines, dots or a spiral.

Concepts: interference, pattern.

An interactive you play with one thumb, on Wundr.