How Tattoos Work

Introduction to How Tattoos Work
A tattoo in progress. mediaphotos/Getty Images

Not too long ago, most Americans associated tattoos with sailors, bikers and sideshow artists. But tattoos have become more popular in recent years, and the people who get them are as diverse as the styles and designs they choose. And some people who would never think of tattooing pictures or symbols onto their bodies use permanent makeup -- a type of tattoo -- to emphasize their eyes and lips.

In this article, we'll look at how the tattoo process works and examine the safety and legal issues surrounding it.

Artists create tattoos by injecting ink into a person's skin. To do this, they use an electrically powered tattoo machine that resembles (and sounds like) a dental drill. The machine moves a solid needle up and down to puncture the skin between 50 and 3,000 times per minute. The needle penetrates the skin by about a millimeter and deposits a drop of insoluble ink into the skin with each puncture.

The tattoo machine has remained relatively unchanged since its invention by Samuel O'Reilly in the late 1800s. O'Reilly based his design on the autographic printer, an engraving machine invented by Thomas Edison. Edison created the printer to engrave hard surfaces. O'Reilly modified Edison's machine by changing the tube system and modifying its rotary-driven electromagnetic oscillating unit to enable the machine to drive the needle.

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Modern tattoo machines have several basic components:

  • A sterilized needle
  • A tube system, which draws the ink through the machine
  • An electric motor
  • A foot pedal, like those used on sewing machines, which controls the vertical movement of the needle.

­When you look at a person's tattoo, you're seeing the ink through the epidermis, or the outer layer of skin. The ink is actually in the dermis, which is the second layer of the skin. The cells of the dermis are far more stable than the cells of the epidermis, so the tattoo's ink will stay in place, with minor fading and dispersion, for a person's entire life.

Next, we'll look at how artists actually create tattoos, from preparation to finishing touches.

Creating a Tattoo: Sterilization

An autoclave sterilizes tattoo equipment before each use.
An autoclave sterilizes tattoo equipment before each use.

A tattoo machine creates a puncture wound every time it injects a drop of ink into the skin. Since any puncture wound has the potential for infection and disease transmission, much of the application process focuses on safety. Tattoo artists use sterilization, disposable materials and hand sanitation to protect themselves and their clients.

To eliminate the possibility of contamination, most tattoo materials, including inks, ink cups, gloves and needles, are single use. Many single-use items arrive in sterile packaging, which the artist opens in front of the customer just before beginning work.

Reusable materials, such as the needle bar and tube, are sterilized before every use. The only acceptable sterilization method is an autoclave -- a heat/steam/pressure unit often used in hospitals. Most units run a 55-minute cycle from a cold start, and they kill every organism on the equipment. To do this, an autoclave uses time, temperature and pressure in one of two combinations:

  • A temperature of 250° F (121° C) under 10 pounds of pressure for 30 minutes
  • A temperature of 270° F (132° C) under 15 pounds of pressure for 15 minutes

Creating a Tattoo: Prep Work

Prior to sterilizing the equipment, the artist cleans each item and places it in a special pouch. An indicator strip on the pouch changes color when the items inside are sterile.

Before working on customers, tattoo artists wash and inspect their hands for cuts and abrasions. Then, they should do the following:

  • Disinfect the work area with an EPA-approved viricide.
  • Place plastic bags on spray bottles to prevent cross-contamination.
  • Explain the sterilization process to the client.
  • Remove all equipment from sterile packaging in front of the client.
  • Shave and disinfect (with a mixture of water and antiseptic soap) the area to be tattooed.

Now, let's look at how the artist creates the tattoo.

Creating a Tattoo: Outline, Shading and Color

The tattoo artist fills in a tattoo using a thicker needle. See the needle in action.
The tattoo artist fills in a tattoo using a thicker needle. See the needle in action.

Clients work with artists to create custom tattoo designs, or they chose images from flash, which are tattoo designs displayed in the shop. The artist draws or stencils the design onto the person's skin, since the skin can stretch while the artist uses the tattoo machine. The artist must also know how deeply the needles need to pierce the skin throughout the process. Punctures that are too deep cause excessive pain and bleeding, and ones that are too shallow cause uneven lines.

The tattoo itself involves several steps:

  • Outlining, or black work: Using a single-tipped needle and a thin ink, the artist creates a permanent line over the stencil. Most start at the bottom of the right side and work up (lefties generally start on the left side) so they don't smear the stencil when cleaning excess ink from the permanent line.
  • Shading: After cleaning the area with soap and water, the artist uses a thicker ink and a variety of needles to create an even, solid line. Improper technique during this step can cause shadowed lines, excessive pain and delayed healing.
  • Color: The artist cleans the tattoo and then overlaps each line of color to ensure solid, even hues with no holidays -- uneven areas where color has lifted out during healing or where the artist missed a section of skin.
  • Final cleaning and bandaging: After using a disposable towel to remove any blood and plasma, the artist covers the tattoo with a sterile bandage. Some bleeding always occurs during tattooing, but most stops within a few minutes.

Health Risks

Precautions for tattoo parlors include glove use, sterilization and covering bottles and tools.
Precautions for tattoo parlors include glove use, sterilization and covering bottles and tools.

Since tattoos involve needles and blood, they carry several risks. These include transmission of diseases like hepatitis, tuberculosis and possibly HIV. When tattoo artists follow all the correct sterilization and sanitation procedures, risks for disease transmission are relatively low. According to the Centers for Disease Control and Prevention (CDC), there has not been a documented case of HIV transmission from a tattoo. However, doctors warn that non-sterile tattooing practices can lead to the transmission of syphilis, hepatitis B and other infectious organisms.

Infections can occur in new tattoos, especially without appropriate aftercare. Some people also experience allergic reactions to tattoo inks. Although the pigments used may have U.S. Food and Drug Administration (FDA) approval for other purposes, the FDA does not regulate tattoo inks. Finally, some people experience pain or burning during magnetic resonance imaging (MRI) examinations because of metallic pigments. Some doctors have also reported interference and distorted MRI images from permanent makeup pigments.

In addition, most states place restrictions on whether people who have tattoos can donate blood. Because of the danger of hepatitis, the American Red Cross will not accept blood from someone who has been tattooed in the past year unless the tattoo parlor is state-regulated. Most states do not regulate tattoo parlors. [Source: American Red Cross]

Tattoo professionals use rules known as universal precautions to prevent the spread of illnesses during tattooing. These precautions are part of the Bloodborne Pathogens Rule issued by the U.S. Environmental Protection Agency (EPA). The same rules apply to hospitals and doctors' offices. The CDC is a good resource for information about universal precautions.

Other precautions specific to tattooing include:

  • Checking gloves for pinhole tears during tattooing, since petroleum-based ointment erodes latex
  • Pouring ink in advance, using clean tissue to open ink bottles during tattooing and preventing nozzles from touching contaminated surfaces
  • Patting tubes dry after rinsing during color changes -- never blowing excess water from them
  • Spraying liquid soap into a tissue, not directly onto bleeding area, since blood can become airborne when the spray hits it
  • Giving pens used for drawing on the skin, which should be medical grade and sterile, to the client

Tattoo artists must also take special safety measures regarding their hands. Gloves help prevent disease transmission from bodily fluids, but bacteria thrive in the warm, damp environment they create. This means that artists must:

  • Wash hands thoroughly and often
  • Inspect hands for cuts or sores and cover them with bandages
  • Remove hangnails and keep nails short to prevent punctures to gloves
  • Refrain from tattooing when experiencing lesions, dermatitis or allergic reactions

Laws require minors to have a parent's permission to get a tattoo. So, some adolescents get tattoos from friends or amateurs, who use makeshift tools like pens and paper clips with little if any sanitary precautions. This is extremely dangerous, since proper equipment and sanitary measures protect people from disease and infection.

Finding a Tattoo Parlor

Reputable tattoo parlors are clean and organized.
Reputable tattoo parlors are clean and organized.

Other than the use of universal precautions and laws requiring minors to have parental permission, few regulations cover tattooing.

Licensing usually involves completing a health department course on infectious disease transmission and passing an exam, but no governing body inspects tattoo businesses. Laws allow anyone to buy a machine, get a license and start tattooing whether or not they have any artistic ability -- a situation that professional tattoo artists object to -- so it's a good idea to do your homework before rolling up your sleeve.

Here are some basic steps for choosing a safe tattoo parlor:

  • Look around to see if the studio is clean and professional.
  • Ask questions: Is there an autoclave? Are the needles and other materials single-use? Are EPA-approved disinfectants used? Do the tattoo artists wear gloves? Professional artists won't mind the questions.
  • Watch the artist and pay attention to health and safety precautions.
  • Watch the artist open all needles before beginning work.
  • Ask about the staff's professional memberships. These are not required, but artists who participate may have the most current information about trends, innovations and safety issues.

Next, we'll explain how to properly care for your new tattoo.

Caring for a New Tattoo

Taking care of a new tattoo can prevent health problems and protect the quality of the image. Most artists give clients a pamphlet that explains all the necessary procedures. Customers generally receive instructions to:

  • Remove the bandage one to two hours after completion.
  • Wash gently with cool or lukewarm water, using a mild antibacterial soap.
  • Pat dry. (Don't rub!)
  • Apply very thin coats of antibacterial ointment and work into the skin. Too much ointment can pull color out of the tattoo.
  • Avoid soaking the tattoo in water or letting the shower pound directly on it.
  • Avoid the sun, sea and swimming pool until healed.
  • Refrain from picking at scabs. They will fall off as the tattoo heals, usually in one to three weeks.
  • Use ice packs if swelling or redness occurs.
  • Call a doctor if you have even the slightest signs of infection.

For more information about tattoos and related topics, check out the links on the following page.

Related Articles

More Great Links


  • FDA/CFSAN: Tattoos and Permanent Make-Up
  • Tattoo knowledge base
  • Mayo Clinic: Tattoos and Piercings
  • Samoa: Tattoos
  • U.S. Centers for Disease Control: CDC's Position on Tattooing and HCV Infection
  • The Vault: Tat Tactics: What Companies think of Your Tattoos
  • Scripps Howard News Service: A Marked Divide