Self Mailers

Pieces usually created from a single sheet that has been printed and folded. For instance, a common practice is to print a page-length advertisement or promotion on one side of a sheet of paper. This is then folded in half or in thirds, with the promotional message to the inside. The two outside surfaces are then used for the address of the recipient and some "teaser" message designed to persuade the customer to open the piece. Source : Wikipedia.com