A tattoo is made by inserting ink about 1.5 to 2 millimeters into your skin, past the outer layer (epidermis) and into the deeper layer called the dermis. A machine drives a needle or cluster of needles up and down at high speed, puncturing the skin thousands of times per minute and depositing tiny drops of ink with each pass. The process involves careful preparation, specialized equipment, and a healing period that can stretch several months before the tattoo fully settles.
Why Tattoo Ink Stays Permanent
The reason a tattoo lasts your entire life comes down to your immune system, specifically a type of cell called a macrophage. Within a few weeks of getting tattooed, nearly all the ink particles in your dermis have been swallowed up by these macrophages, which act as the skin’s cleanup crew. Here’s the surprising part: those macrophages don’t live forever. When one dies, it releases its ink particles, and neighboring macrophages immediately gobble them up. This cycle of capture, release, and recapture repeats continuously throughout your life, keeping the tattoo looking stable even though the individual cells holding the ink are constantly turning over.
This also explains why tattoos are so difficult to remove. Even after laser treatments break apart ink particles and kill the macrophages holding them, fresh macrophages simply recapture whatever pigment remains. The ink never migrates away on its own because, unlike other immune cells, dermal macrophages don’t travel to lymph nodes. They stay put, which is exactly what keeps your tattoo in place.
What Tattoo Ink Is Made Of
Tattoo ink is simpler than most people expect. It’s a pigment suspended in a liquid carrier, usually water mixed with some combination of ethanol or isopropyl alcohol. Glycerol is the most common additive, found in about two-thirds of commercial inks, and helps keep the pigment evenly distributed. Some inks also contain propylene glycol or polyethylene glycol, though these aren’t always listed on the label.
The pigments themselves come from a surprisingly small palette of chemical compounds. One analysis of 54 commercial inks on the U.S. market found only ten unique pigments across all of them. White ink gets its opacity from titanium dioxide. Black ink is carbon black. Reds, yellows, greens, and blues each rely on one or two specific synthetic pigments that get blended to create the full color spectrum artists work with.
The Machines That Drive the Needle
Two main types of tattoo machines exist. Coil machines use electromagnetic coils to pull a metal bar downward in a spring-loaded punching motion. They produce a loud, distinctive buzzing sound and strong vibration. Many artists prefer them for line work because the snapping action can create crisp, sharp lines.
Rotary machines use a small motor to move the needle in a smoother, circular motion. They’re quieter, lighter, and produce less vibration, which makes long sessions easier on both the artist’s hand and the client’s skin. Rotary machines tend to pack color more evenly with less trauma, which is why many artists favor them for shading and large color fills. Modern wireless versions have eliminated the cord entirely, running on rechargeable battery packs that give artists more freedom of movement.
Needle Types and What They Do
Tattoo needles aren’t single points. They’re clusters of fine needles soldered together in specific formations, and each configuration serves a different purpose.
- Round liners group needles in a tight circular pattern for crisp lines and fine details.
- Round shaders use a similar circular arrangement but with slightly more spacing, suited for shading in small or tight areas.
- Magnum needles spread needles in a wider, flat formation for shading large areas and packing solid color efficiently.
Some needles have textured surfaces with small grooves that hold extra ink, allowing more pigment to enter the skin per pass. These are particularly useful for saturating large areas with bold color. The artist selects and swaps between needle types throughout a session depending on whether they’re outlining, shading, or filling.
Step by Step: What Happens During a Session
The tattooing process starts well before the machine turns on. First, you and the artist finalize the design. Any last-minute changes to size, placement, or detail happen now, because once the stencil is made, revisions slow everything down.
The artist then creates a stencil by tracing the design onto transfer paper. Your skin gets prepped: shaved if necessary, wiped down with an antiseptic (typically isopropyl alcohol or a chlorhexidine solution), and thoroughly dried. A thin layer of stencil solution goes on, and the transfer paper is pressed against your skin to leave a purple or blue outline. You’ll check the placement in a mirror, and once you approve it, the real work begins.
The artist sets up the machine, loads ink into small disposable cups, and starts with the outline. The needle punctures the skin rapidly, depositing ink into the dermis with each insertion. You’ll feel a sensation that most people describe as a hot scratching or vibrating sting. For the outline, the artist uses a liner needle configuration, working slowly and precisely to establish the skeleton of the design.
After the outline is complete, the artist switches to shader or magnum needles for shading and color. This phase typically covers larger areas and can feel different from lining, sometimes duller and more like a sustained burning sensation. Throughout the process, the artist periodically wipes away excess ink and plasma with a damp paper towel or sprays the area to keep it clean and visible.
How Pain Varies by Body Location
The rule is straightforward: areas with thin skin, little fat, and lots of nerve endings hurt the most. The ribs, spine, kneecaps, feet, hands, inner elbows, and armpits consistently rank as the most painful spots. The skull, sternum, and groin are also high on the pain scale.
The least painful locations tend to be areas with a decent fat layer and thicker skin. The outer upper arm, shoulder, upper back, forearm, outer thigh, and calf are all relatively tolerable for most people. Your chest and the fleshy part of your back fall somewhere in the low-to-moderate range. Everyone’s pain tolerance is different, but body placement is the single biggest variable in how much a tattoo hurts.
Sanitation and Safety Protocols
A professional tattoo shop follows strict protocols to prevent bloodborne pathogen transmission. The artist wears single-use sterile gloves throughout the procedure, changing them if they touch anything outside the immediate work area. The tattoo machine, its cord, spray bottles, and ink bottles are all wrapped in disposable plastic barriers that get thrown away after each client.
All reusable equipment is sterilized in a steam autoclave. Work surfaces are disinfected between clients, and any blood spills are treated with hospital-grade disinfectant or a 1:10 bleach solution left on the surface for at least 10 minutes. Needles and ink cups are always single-use and disposed of in sharps containers. If a shop doesn’t visibly follow these steps, or if you don’t see the artist open a fresh needle in front of you, that’s a serious red flag.
How Your Tattoo Heals
Healing happens in four distinct stages over roughly six months. During the first week (days 1 through 6), your tattoo is essentially an open wound. Expect redness, swelling, tenderness, and a shiny, wet appearance as plasma seeps from the skin. This is your body’s inflammatory response kicking in, and it’s completely normal.
During the second week (days 7 through 14), the tattooed skin begins to peel and flake, similar to a sunburn. The urge to pick or scratch will be strong, but pulling off flakes prematurely can pull ink out of the dermis and leave patchy spots. Let the skin shed naturally.
From about day 15 through day 30, the tattoo often looks dull, cloudy, or slightly faded. This is the most discouraging phase for first-timers, but it’s temporary. The surface skin has healed over, but deeper layers are still knitting together, and the hazy appearance is just new skin sitting over the ink.
By months two through six, the deeper skin layers finish reorganizing, your skin barrier returns to normal, and the pigment stabilizes in the dermis. The tattoo typically looks brighter and more defined than it did during that cloudy middle phase. At this point, the macrophage capture cycle is fully established, and your tattoo has reached its long-term appearance.