A fitted long sleeve t-shirt cuts close to your body without being tight in a way that actually changes how the piece layers. The fitted cut means the shirt does not add volume under sweaters and jackets. It creates a smooth base layer that other pieces sit on top of cleanly. The fit needs to be accurate across the shoulders and through the bust so it feels good when worn alone and does not shift when layered. The sleeve should be fitted through the bicep without restricting movement. The length should hit at your hip bone. These are the fitted long sleeve t-shirts that layer better than oversized alternatives because they create a streamlined silhouette under other pieces while still being comfortable enough to wear constantly.