Sketch · 2026-06-17
Truchet tiles, on three rules.
Take a square, draw one of two marks in it, repeat over a grid. The marks line up across tile borders without ever being told to, and the field reads as one woven object instead of a collection of squares. Three rule sets are here: Smith's diagonal, Cuevas's two arcs, and a multi-scale variant that lets some tiles subdivide into four.
What you are seeing
The grid is filled tile by tile. For every cell, the generator flips a coin and draws one of two motifs. In Cuevas's rule, the two motifs are mirror images of each other, each made of two quarter-circle arcs joining opposite midpoints of the tile. Because the arcs always terminate at the same four midpoints, the curves chain across borders into a tangle of closed loops and long meanders. Smith's rule swaps the arcs for a single diagonal line, which produces a coarser, more angular field. The multi-scale variant works the same way, except every so often a tile splits into a 2x2 sub-grid and the same coin flip runs on the smaller squares.
The rule
For each cell, pick a random bit. If the bit is zero, draw the first motif; if one, draw the second. That is the whole algorithm. The continuity comes from the constraint that both motifs touch the tile boundary at the same four points: midpoints of the four edges for Cuevas, the two opposite corners for Smith. Any pair of tiles glued together along an edge will line up no matter which motif each one drew, so global structure falls out of a purely local choice.
Things to try
Drop the tile size to 16 pixels and the pattern stops reading as tiles at all, just as a thicket of loops. Push the stroke wide and the negative space becomes the subject: the white loops thicken until they touch. Switch to the multi-scale set and look for the boundaries between coarse and fine zones; the arcs from a big tile still match the arcs from four small ones because every arc lives on a midpoint.
Source
Named after Sébastien Truchet, a Dominican friar who published a tile-based pattern catalogue in 1704. The two-motif version on this page was popularised by Cyril Stanley Smith in The tiling patterns of Sébastien Truchet and the topology of structural hierarchy, Leonardo 20, 1987. The arc variant came from Christopher Carlson and others through the late 1980s and is sometimes credited to the artist Cuevas.