Personalized Coolest Trombone Teacher T-Shirt. The world's coolest trombone teacher in snow capped text with a snowman playing a trombone is a funny design for teachers at birthdays and holidays. 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.