i guess you just have to be careful not to flatten it when you store it or carry it. to be honest, this is my one and only concern about this bag. i am careful not to "squish"it under my arm when i carry it on my shoulder.
my SA put one on hold for me (before i bought it obviously). when i went to look at it, it was dented (apparently they stored it lying on its side and someone put another bag on top of it). i had to wait until they had one that was in perfect condition before i bought it. my advice is just store it properly- make sure it stays upright and that no hard objects dent it.