For thousands of years, humans have been tattooing their bodies. According to Smithsonian.com, several female Egyptian mummies dating back to c. 2000 B.C. have examples of these body modifications.

In SciShow’s video “The Science of Getting (and Getting Rid of) a Tattoo,” host Michael Aranda explains how tattoos stay on your skin permanently and the modern way that this ink can actually be removed.

Read: The Surprising Reason Women Prefer Men With Tattoos As Sex Partners

“Tattoos work by taking advantage of the structure of your skin and composition of the ink that’s used,” Aranda explains. The pigment is applied just deep enough that it won’t flake away over time, as the body’s largest organ naturally does.

The video also reveals the way that laser tattoo removal works. This happens by creating surface heat that breaks up the pigment particles, which are later cleared away by the body’s white blood cells.

Medical Daily previously reported a first-hand account of getting a tattoo removed, calling the entire process “simple, painless, and an overall success.”

Want to know more about how tattoos stay on your skin and the way doctors are able remove them? Watch the video above.

See Also:

Laser Tattoo Removal Before and After: What It’s Like To Erase Your Ink

Tattoos Affect Your Health: Long-Term Side Effects Ink Has On Your Immune System And Disease Risk