Needed a coaster (90mm x 90mm) with plenty of "condensation collection space", so created one with a celtic knot design, except fully three dimensional.

v1 -- lopped off the top of the knot to have a stable surface for the glass to sit. Note that this has gnarly internal overhangs, but seems to print fine.

v2 -- less lopping off the top; seems to still have "enough" stability, though I'm sticking with v1.