First, I have to tell you this wasn't my idea. I spotted it on Pinterest HERE. I thought it was so fun that I had to make a version of my own!
I have every type of paper and envelope imaginable, so I tried 2 different transparent coin envelopes: one vellum and one glassine. The vellum was MUCH easier to stamp on, as glassine tends to not like ink. (The stamp slid around a bit on the waxy surface and it was hard to get a super clear impression.) For confetti, I punched one-inch coral and glittery gold circles as well as black quarter-inch hearts. It's a party and business card in one!