Personalized Engineer White Text Shamrock T-Shirt. A white shamrock made from the word Engineer and small shamrocks is a unique gift design for engineers and engineering students on St. Patrick's Day and at Celtic festivals. 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.