Here are some pics from the yoda tree. I don't think David mentioned the material in the video. It is silicone bronze. Of note, these are all ABS not PLA. Since we can get that nice vapor polished surface finish out of ABS, we wanted to see if we could investment cast it. Turns out you can, at least for small hollow parts. Shiny part is vapor polished ABS, rougher part is 'as-printed' ABS.