What’s really happening under the laser during tattoo removal is much more complex and elegant than it literally sounds (and smells). These days, the best-in-class lasers for the procedure are five-to-six-figure picosecond laser machines, named for the duration of time it takes to heat the ink in your skin—picoseconds, or trillionths of a second. In that time, the laser targets the pigment in the ink, heating it to a temperature it cannot sustain. (If you point a calibrated picosecond laser at a patch of ink-free skin, there is no pigment to attach to and it will do absolutely nothing.) That blood-curdling popping is the sound of the larger ink particles, initially designed to remain in the body forever, shattering into tinier particles. Once they are tiny enough, the ink becomes accessible to the body’s immune processes.

In the months following one of these laser sessions, a healthy person’s system will absorb some of these much smaller ink particles and flush them away, the way it would a mino