For the 24th year, the United States Postal Service is creating a Jazz Fest postal "cachet," a a highly collectible, commemorative mailing envelope featuring a New Orleans musical icon and a silver embossed Jazz Fest logo. Past honorees have been Mahalia Jackson, the Marsalises, the Nevilles and many others. This year's cachet features Kermit Ruffins. The 2012 Jazz Fest postal cachet will be unveiled in a ceremony this Thursday, April 26, at Cafe Istanbul (2732 St. Claude Ave.), at 11 a.m. The event is free and open to the public.