Tattoo
A tattoo is a permanent marking made by inserting ink into the layers of skin to change the pigment for decorative or other reasons. Tattoos on humans are a type of decorative body modification, while tattoos on animals are most commonly used for identification or branding.
Tattooing has been practiced worldwide. The Ainu, the indigenous people of Japan, traditionally wore facial tattoos. Today one can find Berbers of Tamazgha and  Maori of New Zealand with facial tattoos. Tattooing was widespread among Polynesian peoples and among certain tribal groups in the Philippines, Borneo, Mentawai Islands, Africa, North America, South America, Mesoamerica, Europe, Japan, Cambodia, New Zealand and China. Despite some taboos surrounding tattooing, the art continues to be popular in many parts of the world.

# Etymology
The word "tattoo" is a borrowing of the Samoan word tatau, meaning to mark or strike twice (the latter referring to traditional methods of applying the designs). The first syllable "ta", meaning "hand", is repeated twice as an onomatopoeic reference to the repetitive nature of the action, and the final syllable "U" translates to "color".  The instrument used to pierce the skin in Polynesian tattooing is called a hahau, the syllable "ha" meaning to "strike or pierce".
The OED gives the etymology of tattoo as "In 18th c. tattaow, tattow. From Polynesian (Tahitian, Samoan, Tongan, etc.) tatau. In Marquesan, tatu." The first closest known usage of the word in English was recorded in the diary of Captain James Cook in 1769 during his voyage to the Marquesas Islands. The text reads, ...they print signs on peoples body and call this tattaw, referring to the Polynesian customs.  Sailors on the voyage later introduced both the word and reintroduced the concept of tattooing to Europe.
In Japanese the most common word used for traditional designs is, "Horimono".
The traditional Japanese hand method is called, "Tebori".
The word, "Irezumi," simply means, "insertion of ink," and could mean tattoos using Tebori, or Western style machine, (Or for that matter, any method of tattoing using insertion of ink).
Japanese may use the word, "Tattoo," to mean non-Japanese styles.
Tattoo enthusiasts may refer to tattoos as, "Tats," "Ink," "Art," or, "Work," and to tattooists as, "Artists".  The latter usage is gaining greater support, with mainstream art galleries holding exhibitions of both traditional and custom tattoo designs.   Copyrighted tattoo designs that are mass-produced and sold to tattoo artists are known as flash, a notable instance of industrial design.  Flash sheets are prominently displayed in many tattoo parlors for the purpose of providing both inspiration and ready-made tattoo images to customers.

# History
Tattooing has been a Eurasian practice at least since Neolithic times.  Otzi the Iceman, dating from the fourth to fifth millennium BC, was found in the Otz valley in the Alps and had approximately 57 carbon tattoos consisting of simple dots and lines on his lower spine, behind his left knee, and on his right ankle. Other mummies bearing tattoos and dating from the end of the second millennium BC have been discovered at Pazyryk on the Ukok Plateau. Tattooing in Japan is thought to go back to the Paleolithic era, some ten thousand years ago. Various other cultures have had their own tattoo traditions, ranging from rubbing cuts and other wounds with ashes, to hand-pricking the skin to insert dyes.
Tattoos are created by inserting colored materials inside the skin's surface. The first tattoos probably were created by an accident. Someone had a small wound, and rubbed it with soot and ashes from a fire. Once the wound had healed, they saw that a mark stayed permanently.

# Styles
native, religios, wildlife & nature, orintal, symbols, old school, fantasy, portraits

# Purposes

## Decorative and spiritual uses
Tattoos have served as rites of passage, marks of status and rank, symbols of religious and spiritual devotion, decorations for bravery, sexual lures and marks of fertility, pledges of love, punishment, amulets and talismans, protection, and as the marks of outcasts, slaves and convicts. The symbolism and impact of tattoos varies in different places and cultures, sometimes with unintended consequences. Also, tattoos show how a person feels about another person, or how they feel about a relative, preferably mother/father or daughter/son.
Today, people choose to be tattooed for cosmetic, sentimental/memorial, religious, and magical reasons, and to symbolize their belonging to or identification with particular groups, including criminal gangs (see criminal tattoos) but also a particular ethnic group or law-abiding subculture. Some Maori still choose to wear intricate moko on their faces. In Laos, Cambodia, and Thailand, the yantra tattoo is used for protection against evil and to increase luck.

## Identification
People have also been forcibly tattooed for various reasons. The best known example is the ka-tzetnik identification system for Jews in part of the concentration camps during the Holocaust. However, tattoos can be linked with identification in more positive ways. For example, in the period of early contact between Maori and Europeans, Maori chiefs sometimes drew their moko (facial tattoo) on documents in place of a signature. Even today, tattoos are sometimes used by forensic pathologists to help them identify burned, putrefied, or mutilated bodies. Tattoo pigment is buried deep enough in the skin that even severe burns will often not destroy a tattoo. Because of this, many members of today's military will have their identification tags tattooed onto their ribs; these are known as "meat tags".
Tattoos are also placed on animals, though very rarely for decorative reasons. Pets, show animals, thoroughbred horses and livestock are sometimes tattooed with identification and other marks.  
Pet dogs and cats are often tattooed with a serial number (usually in the ear, or on the inner thigh) via which their owners can be identified. Also, animals are occasionally tattooed to prevent sunburn (on the nose, for example). Such tattoos are often performed by a veterinarian and in most cases the animals are anesthetized during the process. Branding is used for similar reasons and is often performed without anesthesia, but is different from tattooing as no ink or dye is inserted during the process.

## Cosmetic
When used as a form of cosmetics, tattooing includes permanent makeup, and hiding or neutralizing skin discolorations.  Permanent makeup are tattoos that enhance eyebrows, lips (liner and/or lipstick), eyes (liner), and even moles, usually with natural colors as the designs are intended to resemble makeup.

## Medical
Medical tattoos are used to ensure instruments are properly located for repeated application of radiotherapy and for the areola in some forms of breast reconstruction. Tattooing has also been used to convey medical information about the wearer.

# Prevalence
Tattoos have experienced a resurgence in popularity in many parts of the world, particularly in North America, Japan, and Europe. The growth in tattoo culture has seen an influx of new artists into the industry, many of whom have technical and fine art training. Coupled with advancements in tattoo pigments and the on going refinement of the equipment used for tattooing, this has led to an improvement in the quality of tattoos being produced.
During the 2000s, the presence of tattoos became evident within pop culture, inspiring television shows such as A&E's Inked and TLC's Miami Ink & LA Ink (Tattoo Tv). The decoration of blues singer Janis Joplin with a wristlet and a small heart on her left breast, by the San Francisco tattoo artist Lyle Tuttle, is taken as a seminal moment in the popular acceptance of tattoos as art.  As seen in the 2007 movie Eastern Promises, body art again features heavily, showcasing the ink-embroidered torso of a Russian Mobster. Tattoos are generally considered an important part of the culture of the Russian Mafia - see ]. 
In many traditional cultures tattooing has also enjoyed a resurgence, partially in deference to cultural heritage. Historically, a decline in traditional tribal tattooing in Europe occurred with the spread of Christianity. However, some Christian groups, such as the Knights of St. John of Malta, sported tattoos to show their alligence. A decline often occurred in other cultures following European efforts to convert aboriginal and indigenous people to Western religious and cultural practices that held tattooing to be a "pagan" or "heathen" activity. Within some traditional indigenous cultures, tattooing takes place within the context of a rite of passage between adolescence and adulthood.
A poll conducted online in July 2003 estimated that 16% of all adults in the United States have at least one tattoo. The highest incidence of tattoos was found among the gay, lesbian and bisexual population (31%) and among Americans ages 25 to 29 years (36%) and 30 to 39 years (28%). Regionally, people living in the West (20%) were more likely to have tattoos. Democrats were more likely to have tattoos (18%) than Republicans (14%) and Independents (12%); approximately equal percentages of males (16%) and females (15%) have tattoos.In the fall of 2006, a study was completed by the Journal of the American Academy of Dermatology.  It found that 24% of Americans who were between the ages of 18 and 50 had a tattoo, which is almost, one in four people in the United states.  Also, in a 1990's article put out by U.S. News & World Report, tattooing, was ranked as the sixth fastest growing retail venture of the 1990s, establishing the tattoo industry as a hot property.However,as of 2008 there is some evidence that the Fashion for tattooing in the Western World may have peaked.

# Negative associations
In Japan, tattoos are strongly associated with the Yakuza, particularly full body tattoos done the traditional Japanese way ("Tebori"). Certain public Japanese bathhouses (sento) and gymnasiums often openly ban those bearing large or graphic tattoos in an attempt to prevent Yakuza from entering.
In the United States many prisoners and criminal gangs use distinctive tattoos to indicate facts about their criminal behavior, prison sentences, and organizational affiliation.
"Tear tattoos," for example, can be symbolic of murder, with each tear representing a death of a friend. Insofar as this cultural or subculture use of tattoos predates the widespread popularity of tattoos in the general population, tattoos are still associated with criminality. At the same time, members of the U.S. military have an equally well established and longstanding history of tattooing to indicate military units, battles, kills, etc., an association which remains widespread among older Americans. Tattooing is also common in the British Armed Forces.
Tattoos can have additional negative associations for women; Although derogatory slang phrases are sometimes used to describe a tattoo on a woman's lower back, it remains one of the most popular spots for a tattoo for females. The prevalence of women in the tattoo industry itself, along with larger numbers of women wearing tattoos, has changed negative perceptions.
A study of "at-risk" (as defined by school absenteeism and truancy) adolescent girls showed a positive correlation between body-modification and negative feelings towards the body and self-esteem.
Leviticus 19:28 is often used to oppose tattoos. This biblical law is strictly adhered to by observant Jews.

# Mechanism
Tattooing involves the placement of pigment into the skin's dermis, the layer of connective tissue underlying the epidermis. After initial injection, pigment is dispersed throughout a homogenized damaged layer down through the epidermis and upper dermis, in both of which the presence of foreign material activates the immune system's phagocytes to engulf the pigment particles. As healing proceeds, the damaged epidermis flakes away (eliminating surface pigment) while deeper in the skin granulation tissue forms, which is later converted to connective tissue by collagen growth. This mends the upper dermis, where pigment remains trapped within fibroblasts, ultimately concentrating in a layer just below the dermis/epidermis boundary. Its presence there is very stable, but in the long term (decades) the pigment tends to migrate deeper into the dermis, accounting for the degraded detail of old tattoos.

# Procedure
Some tribal cultures traditionally created tattoos by cutting designs into the skin and rubbing the resulting wound with ink, ashes or other agents; some cultures continue this practice, which may be an adjunct to scarification. Some cultures create tattooed marks by hand-tapping the ink into the skin using sharpened sticks or animal bones or, in modern times, needles. Traditional Japanese tattoos (Horimono) are still "hand-poked," that is, the ink is inserted beneath the skin using non-electrical, hand-made and hand held tools with needles of sharpened bamboo or steel.  This method is known as "Tebori".
The most common method of tattooing in modern times is the electric tattoo machine, which inserts ink into the skin via a group of needles that are soldered onto a bar, which is attached to an oscillating unit. The unit rapidly and repeatedly drives the needles in and out of the skin, usually 80 to 150 times a second. This modern procedure is ordinarily sanitary. The needles are single-use needles that come packaged individually. The tattoo artist must wash not only his or her hands, but they must also wash the area that will be tattooed. Gloves must be worn at all times and the wound must be wiped frequently with a wet disposable towel of some kind.
Prices for this service vary widely globally and locally, depending on the complexity of the tattoo, the skill and expertise of the artist, the attitude of the customer, the costs of running a business, the economics of supply and demand, etc. The time it takes to get a tattoo is in proportion with its size and complexity. A small one of simple design might take fifteen minutes, whereas an elaborate sleeve tattoo or back piece requires multiple sessions of several hours each.
The modern electric tattoo machine is far removed from the machine invented by Samuel O'Reilly in 1891. O'Reilly's machine was based on the rotary technology of the electric engraving device invented by Thomas Edison. Modern tattoo machines use electromagnetic coils. The first coil machine was patented by Thomas Riley in London, 1891 using a single coil. The first twin coil machine, the predecessor of the modern configuration, was invented by another Englishman, Alfred Charles South of London, in 1899.

## "Stick and poke"
A technique often used for home-made tattoos is "stick and poke": The tip of a sewing needle is wrapped in ink-soaked thread, leaving only the point protruding, and keeping this simple instrument saturated with ink as the skin is pricked over and over, creating a design. The purpose of the thread is to keep the point of the needle coated in ink, increasing the quantity of ink that penetrates the skin. Inks can be improvised from a number of sources such as coal, ashes or shoe polish, but Higgins "Black Magic" waterproof ink is the brand most commonly cited by collectors of so called "India ink" or "stick and poke" tattoos in the US today. Sometimes called "prison tattoos" these tattoos are also popular with gutterpunks, and others associated with the modern hobo subculture, who frequently tattoo visible parts of their bodies, including their hands and faces.

## "Natural" tattoos
According to George Orwell, coal miners could develop characteristic tattoos owing to coal dust getting into wounds. This can also occur with substances like gunpowder. Similarly, a traumatic tattoo occurs when a substance such as asphalt is rubbed into a wound as the result of some kind of accident or trauma. These are particularly difficult to remove as they tend to be spread across several different layers of skin, and scarring or permanent discoloration is almost unavoidable depending on the location. In addition, tattooing of the gingiva from implantation of amalgam particles during dental filling placement and removal is possible and not uncommon. A common example of such accidental tattoos is the result of a deliberate or accidental stabbing with a pencil or pen, leaving graphite or ink beneath the skin.
See Scarification

## Dyes and pigments
Early tattoo inks were obtained directly from nature and were extremely limited in pigment variety. Today, an almost unlimited number of colors and shades of tattoo ink are mass-produced and sold to parlors worldwide. Tattoo artists commonly mix these inks to create their own, unique pigments.
A wide range of dyes and pigments can be used in tattoos, from inorganic materials like titanium dioxide and iron oxides to carbon black, azo dyes, and acridine, quinoline, phthalocyanine and naphthol derivates, dyes made from ash, and other mixtures. The current trend for tattoo pigment favors Acrylonitrile butadiene styrene (ABS plastic) as seen by the widespread popularity of Intenze, Millennium and other ABS pigmented brands.
Iron oxide pigments are used in greater extent in cosmetic tattooing. Many pigments were found to be used in a surveyTemplate:Ref label of professional tattooists. Recently, a blacklight-reactive tattoo ink using PMMA microcapsules has surfaced. The technical name is BIOMETRIX System-1000, and is marketed under the name "Chameleon Tattoo Ink". This same ink can also be found as "The Original Blacklight Inks by NEWWEST Technologies".

## Studio hygiene
The properly equipped tattoo studio will use biohazard containers for objects that have come into contact with blood or bodily fluids, sharps containers for old needles, and an autoclave for sterilizing tools. Certain jurisdictions also require studios by law to have a sink in the work area supplied with both hot and cold water.
Proper hygiene requires a body modification artist to wash his or her hands before starting to prepare a client for the stencil, between clients, and at any other time where cross contamination can occur. The use of single use disposable gloves is also mandatory. In some states and countries it is illegal to tattoo a minor even with parental consent, and it is usually not allowed to tattoo impaired persons, people with contraindicated skin conditions, those who are pregnant or nursing, those incapable of consent due to mental incapacity or those under the influence of alcohol or drugs.
Before the tattooing begins the client is asked to approve the final position of the applied stencil. After approval is given the artist will open new, sterile needle packages in front of the client, and always use new, sterile or sterile disposable instruments and supplies, and fresh ink for each session (loaded into disposable ink caps which are discarded after each client). Also, all areas which may be touched with contaminated gloves will be wrapped in clear plastic to prevent cross-contamination. Equipment that cannot be autoclaved (such as counter tops, machines, and furniture) will be wiped with an approved disinfectant.
Membership in professional organizations, or certificates of appreciation/achievement, generally helps artists to be aware of the latest trends. However, many of the most notable tattooists do not belong to any association. While specific requirements to become a tattooist vary between jurisdictions, many mandate only formal training in bloodborne pathogens, and cross contamination. The local department of health regulates tattoo studios in many jurisdictions.
For example, according to the health department in Oregon and Hawaii, tattoo artists in these states are required to take and pass a test ascertaining their knowledge of health and safety precautions, as well as the current state regulations. Performing a tattoo in Oregon state without a proper and current license or in an unlicensed facility is considered a felony offense. Tattooing was legalized in New York City, Massachusetts, and Oklahoma between 2002 and 2006.

## Aftercare
Tattoo artists, and people with tattoos, vary widely in their preferred methods of caring for new tattoos. Some artists recommend keeping a new tattoo wrapped for the first twenty-four hours, while others suggest removing temporary bandaging after two hours or less. Many tattooists advise against allowing too much contact with hot tub or pool water, or soaking in a tub for the first two weeks. This is to prevent the tattoo ink from washing out or fading due to over-hydration and avoid infection from exposure to bacteria and chlorine. In contrast, other artists suggest that a new tattoo be bathed in very hot water early and often.
General consensus for care advises against removing the scab that forms on a new tattoo, and avoiding exposing one's tattoo to the sun for extended periods; both of these can contribute to fading of the image. Furthermore, it is agreed that a new tattoo needs to be kept clean. Various products may be recommended for application to the skin, ranging from those intended for the treatment of cuts, burns and scrapes, to cocoa butter, lanolin, A&D or Aquaphor. Oil based ointments are almost always recommended to be used in very thin layers due to their inability to evaporate and therefore over-hydrate the already perforated skin. In recent years, specific commercial products have been developed for tattoo aftercare. Although opinions about these products vary, there is near total agreement that either alone or in addition to some other product, soap and warm water work well to keep a tattoo clean and free from infection.Template:Ref labelHowever, salt water can cause a fresh wound to sting as well as leave it vulnerable to infections and fading. 
Ultimately, the amount of ink that remains in the skin throughout the healing process determines, in large part, how robust the final tattoo will look. If a tattoo becomes infected (uncommon but possible if one neglects to properly clean their tattoo) or if the scab falls off too soon (e.g., if it absorbs too much water and sloughs off early or is picked or scraped off), then the ink will not be properly fixed in the skin and the final image will be negatively affected.

## Tattoo removal
While tattoos are considered permanent, it is possible to remove them. Complete removal, however, may not be possible (although many doctors and laser practitioners make the claim that upwards of 95% removal is possible with the newest lasers, especially with black and darker colored inks), and the expense and pain of removing them typically will be greater than the expense and pain of applying them. Some jurisdictions will pay for the voluntary removal of gang tattoos. Gangs will often involuntarily remove gang tattoos, from a person who leaves the gang. Pre-laser tattoo removal methods include dermabrasion, salabrasion (scrubbing the skin with salt),  cryosurgery, and excision which is sometimes still used along with skin grafts for larger tattoos.
Tattoo removal is most commonly performed using lasers that react with the ink in the tattoo, and break it down. The broken-down ink is then absorbed by the body, mimicking the natural fading that time or sun exposure would create. This technique often requires many repeated visits to remove even a small tattoo, and may result in permanent scarring. The newer Q-switched lasers are said by the National Institute of Health to result in scarring only rarely, however, and are usually used only after a topical anesthetic has been applied. The NIH recognizes five types of tattoo; amateur, professional, cosmetic, medical, and traumatic (or natural). Areas with thin skin will be more likely to scar than thicker-skinned areas. There are several types of Q-switched lasers, and each is effective at removing a different range of the color spectrum. This laser effectively removes black, blue, purple and red tattoo pigment. New lasers like the Versapulse & Medlite laser treat these colors & yellow and green ink pigment, typically the hardest colors to remove. Black is the easiest color to remove.
Also worth considering is the fact that some of the pigments used (especially Yellow #7) are known to break down into toxic chemicals in the body when attacked by light. This is especially a concern if these tattoos are exposed to UV light or laser removal; the resulting degradation products end up migrating to the kidneys and liver. Laser removal of traumatic tattoos may similarly be complicated depending on the substance of the pigmenting material. In one reported instance, the use of a laser resulted in the ignition of embedded particles of firework debris.
Some wearers opt to cover an unwanted tattoo with a new tattoo. This is commonly known as a cover-up. An artfully done cover-up may render the old tattoo completely invisible, though this will depend largely on the size, style, colors and techniques used on the old tattoo. Some shops and artists use laser removal machines to break down and lighten undesired tattoos to make coverage with a new tattoo easier. Since tattoo ink is translucent, covering up a previous tattoo necessitates darker tones in the new tattoo to effectively hide the older, unwanted piece.

# Records
The current record for the most studio tattoos in a 24 hour period goes to Oliver Peck of Dallas, TX. Previously, the reality star Katherine Von Drachenberg, also known as Kat Von D, star of the reality TV show "LA Ink" on TLC was the record holder. Her tattoos were of the LA Ink logo while the current record holder's artwork consists of the number thirteen.

# Health risks
Because it requires breaking the skin barrier, tattooing may carry health risks, including infection and allergic reactions. In the United States, for example, the Red Cross prohibits a person who has received a tattoo from donating blood for 12 months (FDA 2000), unless the procedure was done in a state-regulated and licensed studio, using sterile technique.. Not all states have a licensing program, meaning that people who receive tattoos in those states are subject to the 12-month deferral regardless of the hygienic standards of the studio. Similarly, the UK does not provide certification for tattooists, and so there is a six month waiting period without exception.
Modern western tattooers reduce such risks by following universal precautions, working with single-use items, and sterilizing their equipment after each use. Many jurisdictions require that tattooists have bloodborne pathogen training, such as is provided through the Red Cross and OSHA.

## Infection
Since tattoo instruments come in contact with blood and bodily fluids, diseases may be transmitted if the instruments are used on more than one person without being sterilized. However, infection from tattooing in clean and modern tattoo studios employing single-use needles is rare. In amateur tattoos, such as those applied in prisons, however, there is an elevated risk of infection. To address this problem, a program was introduced in Canada as of the summer of 2005 that provides legal tattooing in prisons, both to reduce health risks and to provide inmates with a marketable skill. Inmates were to be trained to staff and operate the tattoo parlors once six of them opened successfully.Template:Ref label
Infections that could be transmitted via the use of unsterilized tattoo equipment include surface infections of the skin, herpes simplex virus, tetanus, staph (Infected Tattoo), fungal infections, some forms of hepatitis, and HIV. No person in the United States is reported to have contracted HIV via a commercially-applied tattooing process. Washington state's OSHA studies have suggested that since the needles used in tattooing are not hollow, in the case of a needle stick injury the amount of fluids transmitted may be small enough that HIV would be difficult to transmit.  Tetanus risk is prevented by having an up-to-date tetanus booster prior to being tattooed. The Centers for Disease Control and Prevention states that no data exist in the United States indicating that persons with exposures to tattooing alone are at increased risk for HCV infection. In 2006, the CDC reported 3 clusters with 44 cases of methicillin-resistant staph infection traced to unlicensed tattooists (MMWR 55(24)).

## Allergic reactions
Perhaps due to the mechanism whereby the skin's immune system encapsulates pigment particles in fibrous tissue, tattoo inks have been described as "remarkably nonreactive histologically".
Allergic reactions to tattoo pigments are uncommon except for certain brands of red and green. People who are sensitive or allergic to certain metals may react to pigments in the skin with swelling and/or itching, and/or oozing of clear fluid called serum. Such reactions are quite rare, however, and some artists will recommend performing a test patch.
For those who are allergic to latex, many artists are using non-latex or will use non-latex gloves if asked.
There is also a small risk of anaphylactic shock (hypersensitive reaction) in those who are susceptible, but the chance of a health risk is small.
Due to the fact that laser removal of tattoo ink causes a release of ink into the bloodstream the risk of anaphylactic shock is also present during removal.

## Tattoo inks
Modern tattooing inks are carbon based pigments that have uses outside of commercial tattoo applications. Although the United States Food and Drug Administration technically requires premarket approval of pigments it has not actually approved the use of any ink or pigments for tattooing (because of a lack of resources for such relatively minor responsibilities).  As of 2004 the FDA does perform studies to determine if the contents are possibly dangerous, and follow up with legal action if they find them to have disallowed contents, including traces of heavy metals (such as iron oxide) or other carcinogenic materials (see CA lawsuit). The first known study to characterize the composition of these pigments was started in 2005 at Northern Arizona University (Finley-Jones and Wagner). The FDA expects local authorities to legislate and test tattoo pigments and inks made for the use of permanent cosmetics. In California, the state prohibits certain ingredients and pursues companies who fail to notify the consumer of the contents of tattoo pigments. Recently, the state of California sued nine pigment and ink manufacturers, requiring them to more adequately label their products.
Acrylonitrile butadiene styrene (ABS plastic) ground down to an average diameter of slightly less than 1 micrometer is used as the colorant in the brighter tattoo pigments. The tattoo pigments that use ABS result in very vivid tattoos. Many popular brands of tattoo pigment contain ABS as a colorant. ABS colorants produce extremely vivid tattoos that are less likely to fade or blur than the traditional pigments, but ABS tattoo pigment is also harder to remove because it is so much less reactive to lasers.
There has been concern expressed about the interaction between magnetic resonance imaging (MRI) procedures and tattoo pigments, some of which contain trace metals. Allegedly, the magnetic fields produced by MRI machines could interact with these metal particles, potentially causing burns or distortions in the image. The television show MythBusters tested the theory, and found no interaction between tattoo inks and MRI.
However, research by Shellock and Crues reports adverse reactions to MRI and tattoos in a very small number of cases. Wagle and Smith also documented an isolated case of Tattoo-Induced Skin Burn During MR Imaging. The person in the case had a dark, concentrated, loop-shaped tattoo, which the authors speculate could have acted as an RF (radio frequency) pick-up; they also note that this is the first such case they encountered in "thousands of MRI studies". Ratnapalan et al. report another case where an MRI could not be completed due to the patient's extensive tattoos. According to the American Chemical society, homemade tattoos, in which metallic inks have been used in larger quantities, cause these reactions.
Professional tattoists rely primarily on the same pigment base found in cosmetics. Amateurs will often use drawing inks such as Higgins, Pelikan or India ink, but these inks often contain impurities and toxins which can lead to illness or infection. A "green haze" is a telltale sign of a tattoo done with drawing ink.

# Temporary tattoos
Temporary tattoos are popular with models and children as they involve no permanent alteration of the skin but produce a similar appearance that can last anywhere from a few days to several weeks. The most common style is a type of body sticker similar to a decal, which is typically transferred to the skin using water. Although the design is waterproof, it can be removed easily with oil-based creams. Originally inserted as a prize in bubble gum packages, they consisted of a poor quality ink transfer that would easily come off with water or rubbing. Today's vegetable dye temporaries can look extremely realistic and adhere up to 3 weeks due to a layer of glue similar to that found on an adhesive bandage.
Henna tattoos, also known as Mehndi, and silver nitrate stains that appear when exposed to ultraviolet light, can take up to two weeks to fade from the skin. Temporary airbrush tattoos (TATs) are applied by covering the skin with a stencil and spraying the skin with ink. In the past, this form of tattoo only lasted about a week. With the newest inks, tattoos can reasonably last for up to two weeks.
Magician Penn Jillette (of Penn & Teller fame) writes in his book Penn & Teller's How to Play in Traffic that he had a special tattoo made on his arm that used no pigment (the tattoo machine was run without ink).  Penn states that the tattoo left a red scar that had a discernible pattern, but would heal to near invisibility after five or six weeks. When filming the remake of Cape Fear, actor Robert De Niro was tattooed with Temptu Ink, a body paint formulated by chemist Samuel Zuckerman.