Although tattoos are permanent, you’ve probably noticed that they lose color and naturally fade over time. That’s because the moment tattoo ink is embedded into your skin, your immune system recognizes the ink as a foreign particle and immediately works to remove it.
However, tattoo ink is placed strategically in the skin’s dermis, the deepest layer of skin, to achieve its permanent design. Although your immune system continuously sends bacteria eating cells to remove the ink particles, the ink particles are much larger in size. Therefore, the bacteria eating cells are only able to scrape tiny fragments of ink away over a lifetime, explaining why tattoos are permanent but fade gradually over time.