Abstract Art Iphone 6/6s case

(V3 is now available https://www.thingiverse.com/thing:2755598)
Hey fellow community members! I made this design because I wanted to spark people's attention. I'm kind of an attention freak ;) however I couldn't find a good way to orient the model for printing to get a smooth back. If you figure it out please comment how you did it.

thanks
Shaya :)