Make a 23x23 square array of points, numbered from 1 to 529 row-wise. Remove all the points whose number is congruent to 0, 1, or 2 modulo 5. Then compute the Voronoi cells of that arrangement of points inside a bounding rectangle. This is the picture you get (use VoronoiMesh[] in Mathematica) https://www.flickr.com/photos/thane/24191215291/in/dateposted-public/ Here's another one with different values of 23, 0, 1, 2, 5, so to speak (unfortunately I forgot to write them down in my enthusiasm) https://www.flickr.com/photos/thane/24191270151/in/dateposted-public/ Anyway, this seems to be a simple way to make lots of interesting looking tilings on the cheap. (1) I can't possibly be the first person to do this...I'd welcome references (2) Can all the wallpaper groups be realized this way? -- Thane Plambeck tplambeck@gmail.com http://counterwave.com/