I've been looking more into how my different t-shirts are constructed and how that affects the fit and comfort. One of the biggest differences appears to be whether the shirt has side seams or a tubular body. Here are my questions: Which of these is best for a muscular build (or, having pectoral muscles)? Which of these is best for a flatter chest? Or does it not matter? If you have any experiences or preferences you would like to share, this is the place.