This is THE shirt to wear under dress shirts!
This is ~THE~ undershirt to wear with dress shirts -- especially if you wear your dress shirts with an open collar, as a previous reviewer stated. The grey heather is PERFECT under all colors of dress shirts, but especially white because it blends better with your skin, resulting in less visibility of the undershirt through the fabric of the dress shirt itself. Ever since I learned this tip years ago, I've been buying these from C-IN2. A deep v-neck (TRUE DEEP) is hard to find in the grey heather color. These wash well, hold up well, and I very much consider these perfection.
This shirt is by far one of the best out there. I've always been a fan of C-IN2. This shirt runs true to size. I'm a medium. Make sure you either hang dry or dry in low heat in dryer.