Mine arrived in a bag, in a foam box similar to the esky. The box was packed with scrunched up newspaper to staop the bag from sliding around too much.
The last ones I picked up from airport arrived bagged inside there own little plastic enclosure thingys, these were padded and placed inside a cardboard box then more padding and another, outer, cardboard box. I thought they were really well packed but AAE said the outer box has to be plastic or wooden! Go figure eh?