When Einstein meets nap time.

The Rest Mass T-shirt captures peak physics humor — a chubby sloth lounging on a chair, representing the only kind of mass that really matters when you’re not moving.

Printed in white chalk-style lines for clean contrast, this design brings theoretical physics down to couch level.

✔ Premium Gildan 64000 cotton
✔ White-only print on black, navy, and royal shirts (also available on white)
✔ Chalkboard aesthetic – solid shapes, no gradients
✔ For physicists, science fans, or anyone who identifies as a stationary object