You saw few my previous work with glass balls to make rasengan or rasen shuriken. Sadly they are way too fragile. One drop and it's over. So I've decided to cast them in plastic. Just for you I'll show part of the process. Here you got the glass ball with the shuriken around it done with my 3D printer in the 1st half of the mould done. It will take some time before making the second half because I need to order more material. :P