CRAQUELURE

A panel arrives with a docket claiming a date. One region of it is painted in a colour that did not exist yet. Find it.

CRAQUELURE is a real Game Boy Color cartridge — a 256 kB ROM you can put on a flash cart — about authenticating paintings. Play three lots free in your browser, right here on this page.

The lamp is the whole game

Every painting is divided into six regions, and each one is painted in a single pigment. Under daylight you can only see the family: lead white, zinc white and titanium white are the same white. Natural ultramarine and French blue are the same blue. That is not the screen being limited. That is true of the actual paint.

So you change the lamp.

Under ultraviolet most of them come apart. Zinc white fluoresces a loud yellow-green. Titanium white goes dead black. Madder lake glows orange. Prussian blue swallows the lamp completely.

Under raking light you stop looking at colour and start looking at the surface. Old hand-ground mineral pigment is gritty. Bitumen tears itself into wide drying cracks. A modern machine-ground pigment is too even and barely crazes at all — and that absence is itself the tell.

Then you check the dates against the docket.

The dates are real, and that is the point

Prussian blue 1706 · cobalt 1802 · chrome yellow 1809 · emerald green 1814 · French blue 1828 · zinc white 1834 · viridian 1838 · cadmium yellow 1846 · alizarin 1868 · cadmium red 1910 · titanium white 1921.

Those are the standard art-historical first-availability dates, and pigment anachronism is genuinely how forgeries get caught — it is what undid Han van Meegeren's Vermeers. So is the awkward fact that natural and synthetic ultramarine are chemically the same compound, which is why no lamp separates them and why the raking light has to exist at all.

Being straight about the rest: the dates are real and so are the best-documented ultraviolet behaviours. The remaining lamp responses are a consistent in-game forensic system, tuned so every group of look-alike pigments comes apart cleanly. This is a game about real art history. It is not a laboratory simulation and does not pretend to be one.

Sixty-four paintings, and nobody drew any of them

Each one is composed by the cartridge's own generator: the fall of the light, the height of the table, which of five vessels stands on it, how the cloth hangs, how the fruit are heaped, whether there is a folded napkin or an open book. Every surface is computed as a lighting model and then dithered down to the two bits per pixel the hardware actually has. The craquelure is generated too — a different network on every tile, crazing according to what that region is painted with.

All sixty-four ship with the download as PNGs, along with the theme recorded off the cartridge.

Some panels are honest

Sign those off. A wrong accusation costs a strike, and so does clearing a panel that was forged. Three strikes ends the shift.

Every case in this cartridge was checked before it shipped: a solver that may only see what the lamps show and what the reference book says — never the answer — was run over 32,000 generated cases, and none of them was unsolvable or ambiguous.

What is in the download

• craquelure.gb — the cartridge, 262,144 bytes, MBC5, Game Boy Color only
• paintings/ — all 64 paintings as PNGs, at 4×
• audio/ — the theme, recorded off the running cartridge, as .wav and .ogg
• a Readme and a licence

It will not run on an original Game Boy, and that is not laziness. Colour is the evidence here: two pigments identical under daylight and different under ultraviolet are identical under both when there is no colour.

Said plainly: this has never been run on physical Game Boy Color hardware. It was developed and verified against an emulator. It is a standard MBC5 image with a correct header and there is no reason to expect trouble, but we do not claim what we have not tested.

Controls

← → choose a region · SELECT change the lamp · B the reference book · A accuse · START sign it off as genuine