I saw this shape on the Antiques Roadshow TV show and thought it would be an interesting one to design for 3D printing. Like most things it was more complicated than it seemed, but on my second try I think I got it. This one printed in just a few minutes over 6 hours using a layer height of 0.200 mm.
I had to create a waffle bottom for it - check that out in the 3D rotation view here: https://youtu.be/XTR7yea_cKI. I posted instructions for making a waffle bottom here: http://birkbinnard.com/blog/do-you-like-waffles-you-should/.