How it's made. A tray of square wells on a 24 mm module, the wells 2.6 mm deep so a 4 mm tile sits proud enough for small fingers to lift. Every tile is cut from the same 22 mm square: two half circles close back into a circle, two triangles are a square, and four quarter tiles make one big circle across four wells - the shapes are fractions of each other and a child finds that out by hand. Made flat in PLA, no supports; tiles print a whole colour to a plate.