I really liked Petclaud's visualisers, so I thought I'd have a go at making one of my own: this is the result. Designed to have an 8x3mm magnet on the back (the keen-eyed will notice I'm using blu-tack when I took the photograph, need to find my superglue...) Now I just need Jo Prusa to have Prusa Orange PLA back in stock.
Don't worry/bother about infill, it's too small for that to be a thing. If it imports not flat to the bed, rotate it positive 90 degrees about the X axis to have it print correctly.
Took an SVG of the triskelion (thanks Wikipedia), imported it into Fusion 360 and then extruded it (basically...) This particular version (v2) I took the time to make it print the right way round and made sure the "dots" behind the heels are attached to the heels equally all round.