This envelope from one of the nation's most vile and persistent junk mailers is actually perfectly flat, clean and undamaged. All of the "stress" has been printed onto the envelope, including the faux detached corner of the faux label. See Exhibit B:
It's like that pre-dirtied clothing all the kids buy! But why? I assume a focus group somewhere responded more positively to a "beat up" envelope than to a clean one.