Mailing Lists: What are the design requirements for sending a postcard through the USPS?
The USPS requires that you do not have rounded corners on your postcards. In addition, you must leave a 5/8 strip along the bottom of the back side of the card for the bar code to be printed, as well as a 3.5 portion on the right-hand side of the back of your postcard for labeling. Do not include a box for the stamp in your design. We do not allow full Gloss Coating on the back side of the postcard. The USPS will not mail designs containing any pornographic or illegal material.