Though the popularity of the internet may have curbed our global use of traditional mailing envelopes, there are still some functions that they provide that can't be replicated by their digital counterparts. Sometimes, you just have to send a physical letter for whatever reason. Those things have to be sealed, though, and the taste of glue sealant has long been the bane of anyone required to use them. Thanks to Flavorlopes, flavored and scented envelopes are now available for purchase.
Clever product design for "Icon Paper and Icon Envelope" by Brigada Creativa, currently in production. It's amazing what some bold black lines will do. A few more pics below: