The poor lowly envelope often takes a back seat to the fancy invitation inside. It's been a goal of mine to try to find a way to fancy up envelopes to match their beautiful contents! And not just with calligraphy, which is an easy out. Here are a few that I've found that fit the bill.
(Gold foil dots. Really elegant.)
(Only concept right now. But how cool! The route between the 2 addresses is mapped!)
(Ahem, leather lined envelopes with a thread closure.
Not sure how these would make it through the mail unscathed...)