Edit, 2016.10.31: The file "...001_eckig.stl" has a hole and probably will not be printed/sliced correctly. In this case try the file "...001_without_hole.stl".
Business card holder;
The photos are showing the first version, but the (2nd) version, has some round edges.
Edit: I've uploaded another Version which should be similar to the first one, but is done with openSCAD (STL + openSCAD downloadable).
Edit 2: Now I've uploaded a new openSCAD version. You can set the "roundess" now to how you like it.
Edit 3: Another new version of the openSCAD-file. You can change the rotation of the bottom now like you want it. Easy going, with some sliders for you lazy ones ;)