Nothing super special, just a nice little bin.
I have grander ambitions to make these in various complementary sizes and shapes, add divider features, make a toolbox system that works with them, etc. While I get around to doing any of those things, however, this is a nice busykeeper for when I'm not quite ready for the printer to print something else.
Print! I've used ABS so far but they'll probably work with anything.
0 extra shells needed.
Fill is mostly irrelevant; it only does any fill in the inside fillet region that joins the walls to the bottom and a little at the top stiffener lip. 25% is fine, 10% or 100% probably okay too.