How Tattoos Ink Your Skin

By R. Siva Kumar - 08 Jul '15 08:11AM

Tattoos have a great image, even though they may be painful. Still, now tattoo machines have evolved beyond the kind of tools that were used in the past, according to yahoo.

An organization called Smarter Every Day took some slow-motion cameras and walked into a tattoo parlour to find out more about the procedure.

Members found that to make a tattoo permanent, the ink has to penetrate into the dermis, or the tissue just underneath the outer layer of the skin called the epidermis. So thousands of tiny pricks are made on the skin with a handheld machine that has a needle, according to businessinsider. .

The artist would dip the needles in the ink, switch on the motor moving the needle, and apply the needles on the skin. The sharp needle would prick the skin repeatedly and drag the ink into the dermis.

The tattoo needle, made of one piece of metal, has many sharp ends. It might have just three ends or 25. Each needle can achieve various effects. Those that have only a few ends are used to outline, while those that have more ends can be used for shading or coloring.

The rotary and the coil are used to move the needle. This is the way it operates: "The coil machine uses a direct electrical current to move the needle. The tattoo artists steps on a foot pedal, which shoots a current into the coil, turning it an electromagnet."

"The now magnetized coil pulls down the metal arm that's attached to the needle, which pushes the needle out. But as the metal arm touches the coil, another thin piece of metal loses contact with a circuit screw, breaking the current and causing the coil to lose its electromagnetic force. The return spring pulls the metal arm back to its original place, pulling the thin piece of metal back into contact with the circuit screw and reconnecting the current that magnetizes the coil. This process happens over and over again as the tattoo artist holds the foot pedal down."

If you see them working in slow motion, you can check how they work. A TED video says that modern tattoo machines pierce the skin at a "frequency of 50 to 3,000 times per minute."

Tattoos disappear if they are applied only on the skin, but the machines tend to overplay their roles. This dermis is "composed of collagen fibers, nerves, glands, blood vessels, and more," according to the video. So a few, large ink particles are distributed in the "gel-like matrix of the dermis," while others are swallowed by fibroblasts, a kind of dermal cell that helps to heal wounds.

As tattoos are making millions of small wounds in the skin, the body's immune system sends special blood cells called macrophages to the tattoo to remove the foreign ink particles. It helps to clean up the body and makes the tattoos fade over time. But it also helps the tattoo stay on in the skin permanently.

Most ink particles that have been eaten by the macrophages go back through the lymphatic highway, taking the consumed particles to the liver for excretion. However, other macrophages don't return to the lymph nodes. Instead, blood cells stay in the dermis, while the ink particles they've consumed are visible.

Check out more in the video below.