Update: I've done a quick improvement and replaced the ring with a Tinkercad generated torus. At least that part should look smooth(ish) now.

A quick relief of the klingon trefoil.
I've not yet printed it, though. I tried to clean it up in Meshmixer, but that only made it more convoluted :-(

I wrote a trefoil using a klingon pIqaD font in Photoshop, then added outward gradients, so the converter could made a relief of it. ([Converter][http://www.thingiverse.com/thing:66115])

I suppose to get a good result, you'd need to design it from scratch - the font picture is too rough and I couldn't smooth ith afterwards. (Though that should be possible - bubblesmooth in Meshmixer looked promising - until it ruined everything half a second later...)