3 × 7 × 11 = 231: a seamless background from three small tiles
A 3×3 tile repeats every 24 pixels. Lay a 7×7 with holes over it and an 11×11 with holes on top, and the maze does not repeat for 1848. Why 231, why 4, 6 and 10 do not work, and why the cells have to be Truchet tiles.