I've published a few box type containers before, but they all had straight sides. Some had rounded (filleted) corners which I liked better. Recently I found a 2D shape called a super ellipse which is similar to an ellipse, but with both rounded sides and rounded corners. So I thought I could use a version of that to make a nice looking box.

When the box was complete I realized it needed to have a lid, so I used the same super ellipse for that, and added a handle that also has an elliptical part on top. Both STL files are included here. The bottom printed in just under 16 1/4 hours, and the top in about 3 hours. For both I printed at 90 mm./sec and a layer height of 0.200 mm.