From left: Ann Taylor Loft linen jacket, $99, anntaylorloft.com. Express polyester–spandex blazer, $148, select Express stores. Ann Taylor Loft piqué jacket, $89, anntaylorloft.com. Isaac Mizrahi for Target seersucker blazer, $40, select Target stores. Plenty by Tracy Reese linen blazer, $235, Tracy Reese, New York City, 212-807-0505.