I printed the case in TPU with 1 bottom layer and 3 top layers. I like letting the infill show through just a little to give the back of the case a pattern while keeping it solid. This works well with TPU but night not work with other materials.

To assemble, print the camera guard separately. It fits in from the inside, and the phone holds it in place. Note that the camera guard is not a perfect square. Put it in the orientation with less horizontal play so the longer edges run vertically. I also added a case that doesn't use the camera guard if you don't want to use it. 

I printed the camera guard in PETG, but I think both parts would work well with most materials.

The back of the case is 1.5mm thick. I tested it with a wireless charger and it worked fine. I don't have any MagSafe accessories, so I wasn't able to test that.