May the (F=mdv/dt) Be with You | Funny Science 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 MICHIGAN ARTISTS & PRINTERS | this design was drawn and screen printed (silk screened) with pride by our skilled illustrators and printers in Ann Arbor. If you're ever in the area, stop by for a free tour and see how we make your apparel! Tagless tag is printed on fabric inside collar, you can't feel it. UNISEX MODERN FIT SIZING | this shirt is slightly tapered to be a little less boxy than the old style of mass-market t-shirt. Nothing drastic, and most people wear the same size in our shirts as they do in all of their others, but you might go one size larger if you're on the fence. It is pre-shrunk, but like any high-cotton product, will still shrink slightly in the wash. Our model photos are the real thing - the actual shirt on our salesguy, Rich. He's 6' 2", 200 lbs and wearing a large SOFT FABRICS | Our shirts are a ringspun, 30/1 fine jersey knit on 100% USA-grown cotton. If you don't speak t-shirt geek, that means they are soft and smooth with a high thread-count, tight knit made out of fuzzy plants grown by American farmers. These are mid-weight shirts - a bit lighter than your mass-market, thick gym class t-shirts, but substantial / not see-through. It's a nice balance between comfort and durability TOP QUALITY INKS & EQUIPMENT | We use QCM screen printing inks, manufactured in Pineville, North Carolina. These are high quality inks - vibrant and durable, and highly crack resistant. Some of our designs are intentionally faded or cracked (see product photos), but our inks always "do what they are told" by our printers. We use top of the line printing presses and ovens (to properly cure inks) made by M&R in Roselle, Illinois SAFE CHEMISTRY | QCM has been one of the most forward-thinking ink manufacturers in the industry, going phthalate-free over ten years ago - way ahead of the curve. They're also CFC free and rated as carcinogen-free by the state of California