Summary

This is a footbag / hacky sack segment pattern as described in a patent from 1979. Two segments stitched together and filled with something like lentils or small beans result in a saggy ball of approx. 50mm diameter.
I cut the segments out of 1mm thin leather and although the leather is very soft the footbag doesn't stay put if dropped. Therefore it is impossible (at least for me at the moment) to catch it by foot without rolling off. It might not be suitable for tricks but it's a lot of fun to hold it up in the air by yourself or with some friends.