Do you remember the Inclusions model I discussed in this topic? As it was very successful (I sold 2 of them ), and most of all, as I like geometrical shapes, I decided to try a different design. In the first version, there was a wireframed tetrahedron with inside an wireframed octahedron, and then the rest of the model was inside this octahedron. In this version instead, I let the octahedron empty. I take advantage of the fact that, by adding this octahedron, there are 4 smaller tetrahedra that are formed to re-iterate the process: I add one smaller octahedron in each of the 4 small tetrahedra. And I go on this process recursively. The result is very close from the Sierpinski pyramid. But I think it is more 3D-printing friendly than the traditional modelling, because instead of removing matter (which can lead to very small sections), I am adding structures (so the model is sturdier and sturdier). Someone from Shapeways' team, correct me if I am wrong... Note that you can just print approximation of a fractal object. This one is perhaps less faithful than the traditional ones (it is between a level 4 and an level 5, I think), but it prints, and - in my opinion - it has still a very aesthetical structure. Here are some more pictures: I have done 2 versions one big and one small (more affordable). You can see both of them in this picture (the previous pictures show the big one): I also tried to do a Menger Sponge with the same idea, but my PC refused to process it :confused. I will try with less polygons, or less iterations.