May The (F=m dv/dt) Be With You | Funny Physics T-Shirt Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 50% Cotton, 50% Polyester Imported Machine wash cold with like colors, dry low heat Check out our store to see all our funny shirts! This is best gift idea for you or a friend. Perfect for Christmas, Father's Day for Dad, Mother's Day for Mom, 4th of July, the perfect idea for your brother or sister. The welcome home gift they will love. Get your humor mode on with this fun t shirt. We have the best funny shirts. With sarcastic and novelty all built into one tee shirt. Looking for that Birthday shirt or just the best cotton tee, you found it. nothing beats an old school shirts that you can Lightweight, Classic fit, Double-needle sleeve and bottom hem