An iPhone SE/5S/5 case that you can cross-stitch any design onto.

I remixed this outer shell case by cutting a grid of square holes in it with OpenSCAD, then exporting a new STL file.

Some of the square holes closed up a bit more than I liked. So after the print finished, I went back and drilled all the holes out with a 1/16-inch bit, then deburred them with a 1/2-inch countersink. I also sanded down the rough surfaces on the inside of the case.