This shirt features a refined mathematical expression for π, written as a double integral in polar coordinates. By integrating over a unit circle, the equation elegantly reconstructs π from the inside out — a powerful fusion of geometry and calculus.

• 100% cotton (fiber blends vary by color)
• Midweight fabric for structure and comfort (170–180 g/m²)
• Tubular construction with taped neck and shoulders
• Reinforced seams on sleeves and hem
• Natural tones may show subtle speckling; white may appear slightly off-white

Each item is printed on demand in order to minimize waste and maximize meaning.
Thanks for supporting thoughtful, math-driven design.

Age restrictions: For adults
EU Warranty: 2 years
Other compliance information: Meets the flammability, lead, cadmium, phthalates and formaldehyde level requirements.

In compliance with the General Product Safety Regulation (GPSR), Oak inc. and SINDEN VENTURES LIMITED ensure that all consumer products offered are safe and meet EU standards. For any product safety related inquiries or concerns, please contact our EU representative at gpsr@sindenventures.com. You can also write to us at 123 Main Street, Anytown, Country or Markou Evgenikou 11, Mesa Geitonia, 4002, Limassol, Cyprus.