UNTUCKit offer some extremely high quality fabrics that when worn untucked look great. One of my favorite formal "untucked" looks it to wear an untucked shirt with a v-neck and a sports jacket. The length of the shirt needs to be about an inch longer than the v-neck and an inch shorter than the blazer.
Dressing It Up. At Hugh & Crye, we often wear an untucked dress shirt with a blazer to make the outfit look a little more sophisticated or formal. The blazer or sportcoat serves as a structured garment that raises the formality of the entire outfit, even if everything else is casual.