How do tattoos stay forever?

In the United States, you can’t get a tattoo until you’re 18 years old. If that seems unfair, just think about it - it’s permanent! As in…forever and ever! For all time! So how does it actually stay on your skin? We asked dermatologist Roopal Kundu to help us find the answer. Got a question that feels like it’s permanently etched in your brain? Send it to us at BrainsOn.org/contact, and we’ll help (th)ink of an answer. See omnystudio.com/listener for privacy information.