Y-3 | MOCK NECK TEE { BLACKY 3 MOCK NECK TEE A MOCK NECK TEE BY Y 3. The loose fit of the Y 3 Mock Neck Tee shapes up with a classic neckline and ribbed cuffs. It's made from comfortable cotton jersey that drapes over the body for a casual silhouette. The cotton in this product has been sourced through Better Cotton. Better Cotton is sourced via a chain of custody model called mass balance. This means that Better Cotton is not physically traceable to end products. Find out more