Check out these quirky yet elegant wedding invitation. With the invitation glued to the envelope, you save time mailing these and also paper! 
I like the one with the cherry blossoms. I’m thinking of getting that one made in India for our wedding. We’ll use the highest quality paper to make it more classy: 
 

 
Also, I could close the envelope with an embossed sticker with the initials M&A. My fiance thinks M&A sounds like mergers and acquisitions.