Birthday postcards for Agents. Our Birthday postcards are printed on a 130LB stock and have a high quality UV coat. Click to select a standard (4.5"X5.5") or jumbo (5.5X8.5") size postcard. Then personalize your postcard using our design center. If you have any questions on our products or our design center, feel free to call us at 1-866-763-8720. We also offer a comprehensive FAQ which should answer most of the commonly asked questions.