Despite primarily being an art form, there is quite a bit of scientific know-how that goes into tattooing. Due to the fact that as tattoo artists we deal with the human skin and its many contradictions, we are tasked with knowing the biology, physiology, and chemistry relating to the tattoo process.
This week’s article will give you a deeper understanding of tattooing; what makes them permanent, why they fade, and how tattoo removal works.
What is the science behind tattooing?
Since we deal with skin, there is an obvious level of knowledge we need to know about its anatomy. Our dye-filled needles pierce a client’s skin at a frequency of 50-3,000 times per minute, so we need to take a lot of care not to scar the body’s biggest organ. The quality and longevity of the tattoo depends on the ink being placed on the right layer of skin.
The epidermis, our outer layer of skin, sheds nearly 40,000 skin cells per hour, which amounts to about a million per day. Therefore if the ink were placed there, it would last only about a month before disappearing. To be permanent, the ink has to travel through to the dermis, the layer just underneath. However, the needle pierces past the dermis, the ink will disperse into surrounding areas, and this will lead to the ink looking smudged or blurry, also known as blowouts.
The artists also have to avoid overworking the tattoo, by having the needle pierce the skin too roughly, due to the machine power being set too high resulting in excessive speed. This will lead to noticeable physical attributes, such as the design having deep pits, raised lines, or scarring.
An experienced tattoo artist is able to perfectly place the ink within the dermis, where it will avoid shedding, blowouts, and scarring. That’s what makes this thick layer of skin the ideal spot for installing a permanent image. While being the ideal spot for the ink, the dermis also is home to nerve endings, which is why tattoos tend to be painful.
Despite the ink being a foreign particle, it manages to avoid being removed by the body’s immune system. This is due to the ink particles being too big for the white blood cells to deal with, making the tattoo a permanent piece of body art.
The white blood cells end up dying when they try to carry these large ink particles. The cell walls of the white blood cells end up making a wall around the ink particles, ensuring that it does not spread.
What makes a tattoo fade?
There are numerous reasons a tattoo may fade or become misshapen over the course of a lifetime. Among them are factors such as the location of the tattoo, the colour and type of pigment, sun exposure, and smoking.
Studies show that exposure to direct sunlight within the first three months of the tattoo (a tattoo’s complete period of healing) can cause the ultraviolet (UV) rays to break down some of the large ink particles in the skin, making it easier for the body’s immune system to destroy them. This will often result in a blurry/discoloured tattoo.
Another cause for fading can be seen when the body goes through a drastic change in size. Rapid volume and mass fluctuations of the body can cause the skin and underlying ink to stretch and then relax when the mass shifts back.
Finally, the biggest contributor to fading is also the most unavoidable, aging. This is due to ink being deposited in the skin, which is 64% water, which causes the particles to migrate in the skin over time. The tattoos will simply fade and fog-out eventually.
How does tattoo removal work?
The process of tattoo removal tends to be way more complicated than getting a tattoo. It involves several areas of study, including thermodynamics, optics, biology, and even chemistry. Due to this, tattoo removals are ideally done by dermatologists, who specialise in the subject.
The process is more painful and expensive than the tattooing process, due to the equipment used and time it takes to completely remove the ink. Dermatologists use very specific lasers for the removal of ink from the body, called picosecond lasers. These lasers bombard the tattooed areas with pulses of light, which break down large ink particles, so that the white blood cells have an easier time engulfing, transporting, and excreting them from the body via the liver.
The views and opinions expressed in this column are those of the author, and do not necessarily reflect those of this publication.