Personalized Mechanical Gears T-Shirt. Mechanical Engineer in gray text and a row of gears below will put your favorite engineer in gear for the day. Unique gift design for your mechanical engineer at birthdays, holidays and graduations. Everyone loves our Custom T-Shirts! Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.