How do tattoos get made? Are they really going to last?
Let’s start by taking a look at how tattoos are made. To make a tattoo, ink is injected into the dermis, which is the middle layer of skin. The epidermis, the top layer of skin, is always shedding cells and getting new ones. The dermis, on the other hand, is pretty stable. When the ink is first put into the body, the immune system sees it as a foreign substance and tries to get rid of it. Most of the ink granules, though, are too big for your immune cells to swallow, so they stay where they are. Tattoos are meant to be permanent, but the ink granules will break down over time and make them look less vivid.
Since tattoo inks are considered cosmetics, they are not regulated by the U.S. Food and Drug Administration and often contain heavy metals and other harmful ingredients. As tattoos have become more common, there are now more colours of ink to choose from, such as red, orange, yellow, light blue, and even fluorescent.
With time and laser treatment, these new colours can change in ways that are hard to predict. Seminars in Plastic Surgery says that some inks have zinc or titanium oxides, which, when treated with a laser, turn black or grey. Most of the time, these tattoos can still be taken off, but it takes more treatments. India ink tattoos, on the other hand, that are black or dark blue are often easier to get rid of with a laser. StatPearls says that laser treatment works well on brown and green tattoo inks as well.
How does a laser get rid of a tattoo?
Lasers were made in 1960, and they can focus light into a narrow beam at a certain wavelength. “Ruby” lasers, for example, give off red light with a wavelength of 695 nanometers. When laser energy hits tattoo ink, it can heat up and break into pieces that are small enough for immune cells to remove. The trick is to do it without hurting too much of the surrounding tissue.
So, how does tattoo removal with a laser work? In general, black materials absorb all colours of light, white materials reflect all colours of light, and red materials reflect red light but absorb other colours. So, a ruby laser can be used to heat and destroy black tattoo ink on a light background, but it wouldn’t be a good choice for getting rid of red tattoo ink. Melanin, the natural colour of the skin, can also soak up laser light. This makes laser tattoo removal harder for people with darker skin. Skin with a lot of pigment is more likely to absorb laser energy and get hurt. This means that there is less laser energy left to destroy the tattoo ink.
The Journal of Surgical Research says that in 1968, a ruby laser was used to remove dark tattoos from people with light skin. Depending on how much laser energy is used, the laser treatment could reduce the amount of tattoo pigment by a lot. However, it could also damage the skin in a way that is similar to second- and third-degree burns. This study used “Q-switched” lasers, which send out bursts of laser energy lasting 10 to 20 nanoseconds. One billionth of a second is 10-9 seconds, which is what a nanosecond is. In earlier studies, tissue damage was worse when millisecond-long pulses of laser energy were used. One thousandth of a second, or 10-3 seconds, is a millisecond. The newest lasers send out light pulses that are only a picosecond long, which seem to work even better. 10–12 seconds, or one trillionth of a second, is what a picosecond is.
The Medical Science Monitor says that right now, tattooed rats are being used to find the best way to treat people.
Not just about tattoos
In 1983, Science published a groundbreaking study about how to use laser technology to remove specific biomedical targets without hurting the tissue around them. Scientists could target tattoo pigments at certain wavelengths by using this idea of “photothermolysis.”
Now, we use Q-switched lasers at 532 nm and 1064 nm to get rid of blue and black pigment in darker skin because melanin doesn’t absorb these wavelengths very well. The 532-nm laser can also get rid of brown, red, orange, and yellow spots on lighter skin. Lasers with wavelengths of 694 nm and 755 nm are used on lighter skin to get rid of black, blue, and green pigment.
Photothermolysis is used to treat spider veins, moles, birthmarks, sun spots, freckles, and tattoos. Often, the same lasers are used to treat all of these things.
Laser removal has its limits
Laser tattoo removal has come a long way and is still getting better, but there is no guarantee that it will work well. Multicolored tattoos can still be hard to deal with, especially if you have darker skin. Laser tattoo removal takes a long time, and insurance doesn’t cover it. Lasers can only affect the top layer of pigment, and it takes the immune system six to eight weeks to get rid of the broken pieces of ink before the next treatment. Many clients need six to ten sessions before they are ready to stop, and some need 20 or more. So, it’s easy for the process to take more than a year.
Tattoos can also be removed with surgery, but even the smallest tattoos usually leave a big scar. But this is often the best choice for people who have developed an allergy to a tattoo or whose tattoo is in a place where fireworks or explosives directly hit them (which may leave flammable fragments). If you hate your tattoo but don’t mind getting a new one in the same place, there are a lot of talented tattoo artists who love to make old tattoos into something new.