Update your closet today with Theory. Shop all the latest designer t-shirts in our selection. Theory uses only high quality materials for its t-shirts, such as cotton, ensuring each piece looks as good as it feels. Look to Theory's range of t-shirts for a simple way to lift your outfit. For enduring style and precise details, look no further than Theory's range of t-shirts. By taking time to care for your cotton, you’ll ensure your item remains in pristine condition for years to come. Simple steps are required to prolong the life of cotton long sleeve t-shirts, we suggest always checking the label to ensure no specific care instructions are required. Cotton is durable, soft and comfortable, but it does need to be cared for properly to ensure it doesn’t shrink. We recommend hand or machine washing in cold water of 30°C or below. Choosing a cycle at this temperature will prevent shrinkage, as well as helping to avoid colour fading and dye transfer on bright or dark items. Allow to air dry naturally, and give garments a gentle stretch to restore shapes as soon as they come out of the wash. Our edit of Theory t-shirts features a whole host of unique yet easy-to-wear pieces. Shop all your favourites right here.