Stampville: Aurélien Débat's City in Two Inks

By Ali Kaya

Stampville is a matchbox-style box with twenty-five wood-backed rubber stamps in different shapes and textures and a double ink pad, one side yellow and one side blue — and that is the whole kit. Nothing to plug in, nothing to charge. The reason it works so well, I think, is that it gives you parts of buildings rather than buildings, so the house is something you have to put together yourself.

Aurélien Débat was born in France in 1979, studied illustration at Les Arts Décoratifs in Strasbourg and now lives and works in Marseille; before the stamps he wrote and illustrated children's books. His architectural drawings are built from simple hatching and flat fills that leave the white of the paper alone, and he had already drawn La Grande-Motte, building sites and transport before he cut that same vocabulary into rubber. Each stamp is one architectural element — a piece of wall, a roof, a patch of ground, a texture — and lined up in the box they read less like a toy and more like a type case, an alphabet you set a city with.

The bench below is not a copy of Débat's stamps — the shapes are mine — but it works the way the box does. Pick a stamp, pick an ink, press it onto the sheet, and stamp over what is already there.

Two inks, three colours

Where the yellow and the blue land on top of each other the paper turns a dark green, and nobody put green in the box. Ink does not add light, it takes light away — each layer absorbing part of the spectrum and letting the rest bounce back from the paper. Yellow ink swallows the blue end of white light, blue ink swallows most of the red end, and what survives both layers is the narrow band in the middle our eyes call green. That is why the overlaps come out darker than either ink on its own, and why Débat can print what looks like a three-colour town with two pads. If you like colour pinned down and named, there is a whole pre-photographic system of it in Werner's Nomenclature of Colours.

Two stripes, a third pattern

The stamps that interest me most are the hatched ones, because hatching printed over hatching does something plain shapes never do. When two sets of fine parallel lines overlap at a slight angle, a much larger set of broad bands appears across them — a moiré — and those bands are in neither stamp. For two identical line sets with spacing p crossed at an angle θ, the bands repeat every D = p / (2 sin(θ/2)), so the smaller the angle the wider the bands: at a few degrees, a roof hatched in 1-millimetre lines can carry stripes more than a centimetre apart. Turn the second stamp with the slider and watch a tiny change in angle move something far bigger. The same trick, animated, drives Takahiro Kurashima's Poemotion.

How infinite is infinite

The box promises that the combinations are infinite, and as a maths teacher I cannot leave a sentence like that alone. Twenty-five stamps, two inks and four ways to turn each stamp give 25 × 2 × 4 = 200 different impressions, and because ink stacks the order matters: a blue wall over a yellow roof is not the same picture as a yellow roof over a blue wall. A modest street of ten impressions then has 200¹⁰ ≈ 1.02 × 10²³ possible sequences — about a sixth of Avogadro's number, the count of particles in one mole of a substance — and that is before you decide where on the page any of it goes. The positions are what really make it infinite, since a stamp can land anywhere, so the box is right, only for a better reason than the one it gives.

Inside, along with the stamps and the pads, there is a fold-out sheet of ideas, and the whole thing is 27.9 centimetres long and 9.5 wide, published by Princeton Architectural Press — small enough to slide into a drawer, and long enough that a street fits across the lid.