I made a protective mobile case out of soft leather.
The leather is cut with a laser cutter and I designed the pattern in OpenSCAD to made it able to adapt to different phone sizes. A ready made dxf for my phone (Sony Xperia Z3) is available. Any other phone should work as well, but you need to change a few parameters in the .scad file and compile it to a new dxf file.
You will need:
You may be able to skip the laser cutting and cut the piece by hand. Nice thing about laser cutting are the perfect spaced holes. But maybe it can be done by hand with some thin soft leather...
If you have a Sony Xperia Z3 you can skip this step and just download the ready made .dxf.
If not, you need to install OpenSCAD to you computer, open the attached .scad file and change a few parameters (everything is metric/mm):
You rerender the file with F6. If you are happy, use the export function to create you .dxf file.