For more than 10 years I have dedicated part of my time to design sliceforms. In this case, I present some cardboard solid spheres based on the stereographic projection. Note that all cross sections of the sphere are circles. Hence, if we want to build a physical model of the sphere, we need planar curves that map to circles on the sphere via the stereographic projection. These planar curves are either lines or circles. In this paper, I consider some specific lines contained on a plane whose projection on the sphere is used as templates to reproduce a real model.

Templates of these and other models can be downloaded in .pdf format from my website.

Finally, I have recorded a tutorial explaining how to build the models.