There's only one outfit we know Kate Middleton always packs, and that's something black. This is on purpose, because according to The Independent, the royal family is required to pack a black outfit for mourning. The strict rule's in place in case anyone in the family dies while they're away. That way, he or she can change into the spare attire upon arrival in England. As morbid as all this sounds (who wants to think about this while traveling?), you have to admire the royals for being so prepared, especially since Prince William and Kate are often abroad.