The most common simplification is that the tattoo needle injects ink deep enough into the skin to stay in place. Now when you get a tattoo, the tattoo needle basically creates small wounds on the skin. The tattoo needle pierces the epidermis of the skin, delivering ink to the second layer of skin, the dermis. A tattoo is a permanent image formed on the skin by a needle that injects ink into the dermis.
Tattoo ink tends to remain static in the skin. However, as time passes, some inks may move deeper into the dermis. When this happens, the tattoo takes on a faded appearance. If the tattoo is exposed to harsh sunlight, then the ink may break up, and this can cause skin problems while fading the color.
When a tattoo needle pierces the skin, it tears through the epidermis, the outer layer of the skin, and pours the ink into the dermis, the inner layer of the skin filled with blood vessels and nerves. As already mentioned, the ink is transferred to the skin with a tattoo needle at a fairly high speed. Although tattoos were made by hand, piercing the skin with a needle and manually injecting ink, tattoo artists now use tattoo machines that quickly pierce the skin and inject the ink at the same time.
Ink-filled Needles Transmit Tattoos
Ink-filled needles infuse color into the skin, allowing tattoo artists to create permanent designs, images and masterpieces. The tattooist dips an electric needle into the ink, quickly and repeatedly creating thousands of tiny punctures in the skin. With each puncture, a small amount of ink is injected into the skin with a needle.
A tattoo tool with a needle pierces the skin at a speed of 100 times per second, leaving ink pigments 1.5–2 mm below the skin surface. The needle penetrates the skin through the epidermis and into the papillary dermis, where ink particles accumulate. The tattoo machine’s needles pierce 50 to 3,000 times per minute through the epidermis, the outer layer of the skin, and direct the ink into the dermis, the deepest layer, saturated with nerves and blood vessels. The needle passes through the outer layer of the skin where it reaches the inner layer or dermis.
If the ink only reaches the epidermis (the first layer of skin), a permanent tattoo will not be permanent, as that layer of skin is constantly shed and replaced. The ink that enters the epidermis of the skin is removed by white blood cells over the next 7-14 days. The ink doesn’t just stain skin cells, because these cells die and are replaced over the years. The ink does not stain the skin cells as many people thought.
Certain Cell Types Absorb Tattoo Ink
Other cells and parts of the skin, such as fibroblasts, absorb the tattoo ink. Some tattoo ink gets inside skin cells called fibroblasts and macrophages. Ink not removed by special repair cells called macrophages remains in the dermis inside trapped macrophages or skin cells called fibroblasts.
In healing mode, the body sends a group of blood cells called macrophages to the tattoo site to remove foreign bodies (ink particles) in the dermis. Jonathan Bennion goes on to explain that when white blood cells called macrophages die, they secrete the foreign ink, and a new macrophage emerges to engulf it — or at least most of it, and occasionally carry Ink particles enter the lymphatic system. Some macrophages return to the liver to remove ink waste, while others roam the tattoo site.
Some of the larger ink particles are dispersed in the dermis to create the tattoo, while others are taken up by cells called fibroblasts. Some of the ink particles are eventually taken up by fibroblasts, which are a type of skin cell that helps heal wounds, but not enough to make the tattoo disappear. Presumably, the ink particles eventually move into the deeper layers of the dermis due to the action of mobile phagocytic cells (for example, immune cells), due to which the tattoo becomes bluish, faded and fuzzy.
None of the Body’s Cells Can Destroy the Ink
Because others cannot dissolve the ink’s pigments, the ink remains visible through the skin. Because dermal macrophages cannot break down the ink, they thwart the immune system’s attack by staying in place in the second layer of skin, locking the ink in their vacuoles. When immune cells called macrophages wither, they leave ink between skin cells, like when you get your first tattoo. Dermal dendritic cells are primed to initiate a response to injury, such as that caused by tattoo needles entering the skin and injecting pigment.
In the dermis, ink-containing phagocytes are concentrated under a layer of granulation tissue surrounded by collagen along the epidermis-dermis junction. Initially, the ink is taken up by keratinocytes and phagocytes, including fibroblasts, macrophages, and mast cells. It is important to note that after tattoo ink infusion, bound pigment particles can leave the skin through their vasculature and enter the lymphatic system (nodes).
The tattooing process involves injecting the desired color of ink pigment into the dermis layer of the skin. Insertion is done by dipping the tattoo needle in colored ink before applying it to the skin. In laser tattoo removal, a laser sends short pulses (down to a trillionth of a second) that strike the ink particles and break them up.
Tattoos can be destroyed with a laser that penetrates deep into the skin, breaking the ink fragments into smaller particles that are more easily carried away by these macrophages. An experienced tattoo artist can minimize the amount of ink entering the veins by injecting the ink to the correct depth.
