Everything we draw on our skin clears completely within hours, days, or a month at most. Hennas, body paint, makeup, etc. Everything, but tattoos. This makes us wonder, what makes tattoos permanent?
Are tattoos permanent because the tattoo ink is injected into the skin, and not drawn on it?
To understand why tattoos are permanent, we need to understand the anatomy of the skin and how each layer of the skin interacts with the tattoo ink.
Let’s dive in.
The Anatomy of the Skin
The skin is made up of three layers.
- The epidermis
- The dermis and
- The hypodermis or the subcutaneous layer
Each layer of the skin is unique and distinct from the other- all thanks to the tissue they are made of. The nature of each layer affects your tattoo ink. It is what determines if your tattoo will stay put, fade or smear.
Let’s discuss each layer, so you’ll understand what we mean.
The epidermis is the layer of the skin you see. Of the three layers of the skin, it is the thinnest.
This protective layer of the skin is made of a tissue called the epithelial tissue, which is a highly cellular tissue.
By highly cellular, we mean that the cells in this tissue are packed together and stacked on top of each other.
Here’s something you’ll find interesting:
The cells in the epidermis copy and replicate themselves.
As they replicate themselves, the old cells get pushed up closer to the surface of the skin where they flatten out and die because they are cut off from the blood supply. The dermis is avascular- it doesn’t have any blood vessels within it. That’s why the cells in that layer of the skin flatten out and die.
But these cells shedding (flattening out and dying) isn’t a bad thing.
On the contrary, it’s good because it’s the dead cells that prevent friction and abrasion when we rub our skin against each other or against an object.
Fun fact: Every day, we shed about a million cells!
The Epidermis and Tattoo Ink
Millions of cells on the dermis are lost every day.
The average lifespan of the cells in the epidermis is 3-4 weeks. This explains why everything we draw on the skin fades/ cleans off completely within 4 weeks.
If tattoo ink is injected into this layer of the skin, it will be futile because within a month it would have cleared off.
Let’s talk about the next layer.
The dermis is made of ‘dense irregular connective tissue’.
The nature of the dermal tissue allows tattoo ink to stay put within it.
Here’s what you should know about the process of tattooing.
Tattoo ink, which is foreign to the body, is injected into the skin using a tattoo needle.
The process of introducing tattoo ink- injection- is traumatic to the skin.
The body reacts to trauma and foreign bodies by activating an inflammatory process. This process sends white blood cells (macrophages) to the site of the trauma.
Think of the white blood cells as an Army. The army defends and protects a region from foreign invaders, right?
That’s the same thing the white blood cells do.
When tattoo ink is introduced into the body, the white blood cells (macrophages) which constantly tour the body are notified, and they immediately move to the area the tattoo ink was injected.
The Dermis and Tattoo
White blood cells deal with foreign substances by engulfing them. In technical terms, this process is called phagocytosis.
(When we say foreign bodies, we’re referring to things that shouldn’t exist in the body. Things like bacteria, viruses, etc.)
Usually, after engulfing the foreign substance, the white blood cells break it down and digests it. But white blood cells break down only biological organisms like viruses and bacteria. It can’t efficiently break down tattoo ink.
So, what does the body do?
To prevent the tattoo ink from moving to other parts of the body, your immune system isolates the tattoo ink by keeping them engulfed in the white blood cells.
This is why your tattoo stays in the same place it was drawn, without fading significantly over the years.
Of course, white blood cells die. They don’t last for the lifetime of your body.
So, what happens to the tattoo ink when the white blood cells which engulfed them dies?
Does the tattoo ink roam freely around the body then?
When the macrophages die, they release the tattoo ink. Immediately, new macrophages engulf the tattoo ink again.
Now, you should understand that although the now-dead macrophages didn’t completely break down and digest all the tattoo ink, they tried. It broke down some.
So, when the macrophages die, some of the tattoo ink it broke down find their way to the lymphatic vessels.
We know this because, as Jonathan from the Institute of Human Anatomy said, biopsies have been done on distinct lymph nodes and tattoo inks were found.
This cycle of engulf-release-engulf diminishes the tattoo ink, causing your tattoo to fade significantly over time.
The hypodermis or subcutaneous layer is made up of adipose or fatty tissue. Because of the oily nature of this layer, it’s not a good place to inject tattoo ink.
Injecting tattoo ink into the hypodermis causes tattoo blowout.
The Hypodermis and Tattoo
Do you know what a tattoo blowout is?
In case you don’t, a tattoo blowout is when the lines of a tattoo become poorly defined, causing the tattoo to look blurry. It is caused when a tattoo artist exerts excess pressure while tattooing, causing the tattoo ink to be injected into the hypodermis.
So How do Tattoos Become Permanent/ Long-lasting?
Tattoos become permanent when they are injected into the dermis. The nature of the dermis and the mechanism of the immune system makes this possible.
The quality of the tattoo ink and the expertise of the tattoo artist also affect the life span of a tattoo.
What Layer of The Skin Should the Tattoo Ink Be Injected?
The structure and nature of the dermis allow the tattoo ink to stay put there for years, without fading significantly.
If the tattoo ink is injected into the epidermis, it will fade completely within a month. If injected into the hypodermis, it will become blurry. For a long-lasting, clearly defined tattoo, the tattoo ink should be injected into the dermis.
Are tattoos permanent?
No, tattoos don’t last forever. They fade with time. We’ve earlier discussed that tattoo ink fades over time because of the activities of the macrophages and immune system.
Tattoos can also be removed.
There are different tattoo removal options, but laser tattoo removal is the best. We highly recommend it because it is non-invasive and safe.
To learn about how laser tattoo removal works, read this article.