What is a rain shirt? An Outlier Experiment in limited run, the Outlier Soft Core Rain Shirt is a best-of-both marriage of their Soft Core Wool Vest and the Supermarine Rain Shirt. In other words, superfine Merino wool on the inside, breathable Primaloft Infinity insulation, and an exterior of highly water-resistant cotton whose fibers expand when wet to repel moisture. That, plus Outlier’s patent-pending Pivot Sleeve construction for freedom of movement, and a tailored shirt dress shirt look. A city slicker…