Summary

I designed this case earlier this year in Onshape, building from scratch using a model. I also made a cello sketch using a picture and then cleaned it up for this.

Here's a link to the Onshape document:
https://cad.onshape.com/documents/135651eda25ac97ccf91ddfb/v/6215bc82e19412aa735be150/e/f8edaeff7010cb26f8147f78

The case in the picture has PLA on the bottom, and then TPU for the top layer of the base and then the walls. It was designed with thicker walls than normal, so it holds up pretty well. Taking it in and out can start to peel away the TPU however, as seen at the lightning port end of the case.