Love the natural invites (the brown) and the idea of the fabric (or other cool paper band, like the other light pink one I tagged before). Also love the RSVP card attached with ribbon in front (and that it's online RSVPing to save paper and cost).
Convites de casamento criativos para você se inspirar
I dont know if the Post Office will like you for this one, but these invitations have been wrapped in hand sewn canvas bags. The addresses and stamp have been printed onto iron on-fabric transfer paper (the invitations were printed on real wood!