TLDR;

A bathroom catch box to collect used razor blades.

openSCAD

I was just looking for a nice way to hollow objects in openscad and it ended up with this clean box to collect used razor blades.  

openSCAD

include <BOSL2/std.scad>
$fn=90;

module razor_drop(w=1.35){
    module cube2(d=0){ // shaped like an old razor blade
        cuboid([84,26,100]-[d,d,d],rounding=w*2);
        cuboid([74,42,100]-[d,d,d],rounding=w*2);}

    zrot(90)union(){
        difference(){
            up(40)yrot(-45)
            difference(){
                cube2();
                cube2(w); // hollow
                translate([20,0,52])yrot(45) // cut the slit
                    cuboid([2,30,10], rounding=1, except=[TOP,BOT]);
            }
            cuboid(100,anchor=TOP);
        }
        intersection(){ // add the bottom
            up(40)yrot(-45)cube2();
            cuboid([100,100,w], anchor=BOT);
        }
    }
}//
razor_drop();