These guides are meant as a toolkit to help you be the best client and learn how to work with your tattoo artist to create the tattoo of your dreams. Remember: No matter what you read on the internet, your artist’s advice should be considered the gold standard.

The science behind a tattoo is one of the oldest processes in history, even if our ancient ancestors didn’t entirely know the biology behind their art. Just as people have been mixing pigment with various locally found ingredients since the first cave paintings were done, tattooing has been a part of cultures across the world for a very, very long time. But how does a tattoo actually stay in your skin?

1. Your skin has three layers.

The first, outermost layer is your epidermis, a waterproof barrier that protects and provides skin tone. The second is your dermis, filled with connective tissue, glands, and hair follicles. And your last, deepest layer is your subcutaneous tissue, containing more connective tissue and fat.

2. The tattoo needle is puncturing through your top layer of skin into the second layer.

Your dermis is static, whereas your epidermis changes. Think about sun burns, exfoliating rubs, allergic reactions. Unless you’ve got something deeper going on, your dermis doesn’t change with your excessive tanning (too much) or fancy face rubs, making it the perfect, permanent ground for injecting ink into.

3. Your body’s natural healing abilities help keep that tattoo stable.

Tattoo needles, carrying ink, puncture into that dermis and your body goes on a healing spree immediately. White blood cells travel through your bloodstream to heal the site of the open wound — which is essentially what a tattoo is — bringing with them tiny cells called macrophages. Macrophages basically eat the pigment and any other invaders, with the intention of helping your body process out anything that might be a foreign contaminant. Those little consuming macrophages, as well as some free hanging pigment, wind up trapped in the gel matrix of your dermis, visible through the epidermis.

4. Your outermost skin initially has ink in it, then pushes the ink out and heals.

Think about the first week or so of having a tattoo — you have a very pretty scab that eventually turns into a really crunchy scab. This is all part of the skin’s healing process, and paying attention to what your artist explained for aftercare is key. Eventually, your epidermis will heal completely free of ink, letting your tattoo shine cleanly through. Proper hydration, cleanliness, and following your artist’s orders will make sure you don’t mess with the healing process. A scab that goes deeper than the epidermis has chances of leaving permanent keloids — a bundle of overhealed skin — unless treated properly.

5. Your pigment cells are constantly regenerating.

The ink is being held inside your skin — literally on a cellular level. Your cells are constantly regenerating, which is what gives you that youthful bright look, but the way your skin cells regenerate is by replacing each other. Rather than pushing old cells out of the way, your skin cells are simply consuming the old cells — thus leaving the tattoo pigment in place. Of course, this process, coupled with aging and sun exposure, will lead to some natural fading.

And this is why your tattoo sticks around, despite even some natural and light wear and tear. Proper aftercare, listening to your tattoo artist, and sunblock will aid in your work of art’s permanence.