Tattoos, explained

Tattoos last because immune cells trap ink beneath the skin—but there's more to the story. This overview looks at how ancient cultures used tattoos for status, spirituality and punishment; how technology like the electric tattoo machine transformed the art form, and where innovations like smart tattoos could take it next.

Samuel O’Reilly patented the tattoo gun in 1891

Before the tattoo gun's invention, recipients sweated while artists slowly tapped or sliced designs into their flesh. The tattoo gun changed the field, helping artists ink clients’ skin at incredible speeds. Inventor Samuel O’Reilly applied the basic idea of an electric pen invented by Thomas Edison to his tattoo gun.

Tattoos suppressed during colonization are experiencing a revival

A few decades ago, the distinct facial tattoos worn by Maori people were on the brink of disappearing. Then, Maori artists brought the cultural practice back into the spotlight. This TVNZ story follows one reporter’s mother as, at 59 years old, she receives tā moko from a Maori artist.

Tattoos were once used to identify status

Around 450 BCE, Scythians inhabiting what is now southern Siberia were recorded as wearing tattoos of swirling mythical beasts to signify nobility. At the same time, tattoos have identified lower-status and enslaved people.

'Skin stitching' is an ancient tattoo method that's made a comeback

In the slow method, artists use needles to puncture the skin. Then, pigmented thread is drawn through the punctures to create the tattoo, resembling embroidery in the flesh. The method is experiencing a cultural revival within Canada’s First Nations communities.

Sailor tattoos represent naval milestones

Sailors often come home with mermaids or turtles adorning their bodies. But what does it mean to have permanent images of propellers on your bum, British galleons with soaring tiers of sails on your chest, or a bicep portrait of the Roman god Neptune? Those tattoos represent meaningful naval milestones.

Tattoos are made by injecting pigments into the skin

Tattoo ink is injected under the skin, which can leave the body open to infections and allergic reactions. While many tattoo artists are licensed professionals who follow sanitary guidelines, that’s not always the case.

The immune system fights tattoos

Our skin is a fascinating organ that wants nothing more than to protect our bodies from the outside world. Tattoos penetrate that protective wall to inject ink directly into the sensitive, immunologically rich layer of skin known as the dermis.

How 'the Iceman' got his tattoos remains a mystery

Ötzi the Iceman, discovered in 1991, is one of the oldest human mummies ever found—and his 61 tattoos remain a mystery. This explainer looks at how researchers believe the tattoos were made, what their placement suggests about ancient medicine and culture, and why we’re still piecing together their true purpose today.

Tinnitus is derived from the Latin verb tinnire, meaning to ring

Read the entry in The Physical Dictionary by Stephen Blankaart, from 1693, where the word first appeared in English.

The world’s oldest tattoos belong to 'Iceman' Ötzi

Ötzi is the corpse of "the Iceman" found in the Alps along the Italian and Austrian border in 1991. His mummified body was covered with lines and crosses along the “hard-working” areas of his body, signifying their potential application for therapeutic pain management.

Tattoo removal breaks apart ink particles

Tattoos place ink below the skin's surface layers in packets too large for white blood cells to clear out. By breaking the ink into smaller pieces, the immune system, which is responsible for removing foreign matter, can process them.

Harvard and MIT researchers are developing life-saving tattoos

Tattoos aren’t just a fashion statement. Scientists are trying to find life-saving applications for them. Harvard and MIT researchers are developing tattoo inks that react to body chemicals, alerting diabetics to blood sugar fluctuations or athletes to dehydration. Someday, patients may observe their body chemistry with tattoos that change colors.

Technological breakthroughs are spurring innovations in the industry

What if you could see your tattoos before they’re embedded in your skin? Or take a virtual visit into a local studio to work out your nerves over a first tattoo? The industry is anticipating some big technological changes, from 3D designs to sci-fi upgrades to more precise tattoo guns.

The body can remove tattoos after they are broken down by laser

Tattoos place blobs of ink below the surface layers of the skin in packets too large for white blood cells to clear out. By breaking the ink into smaller pieces, they can be processed by the immune system, which is responsible for removing foreign matter.

Women in WWII used tattoos to avoid capture

During World War II, Japanese soldiers kidnapped women from Southeast Asian countries and forced them into sexual slavery. But they hesitated to capture married women, a fact that women from the island of Timor exploited, painstakingly poking tattoos onto their bodies that marked them as married women.

'Magic ink' is redefining the tattoo

One University of Colorado professor has developed an ink that can be "turned on" with exposure to UV light, and "turned off" with sunlight. While the ink could help those who want to hide their body art from family members or coworkers, there are potential uses for medical procedures.

The centuries-old history of titanium white goes back to the Inca

Titanium white can be found in items ranging from paint to pills. Though it was created in New York in 1908, the pigment was first used hundreds of years earlier by the Inca, according to this article.

Watch the engineering challenges overcome in turning a 3D printer into a tattoo machine

The DIY project required reprogramming the printer to operate on a curved, 2D surface rather than making flat layers in 3D, editing replacement firmware to bypass temperature safety checks, and developing a rapid system to stop the tattoo in case of an emergency. The final product printed "LEG" on a volunteer's leg.

'Graffiti' comes from the Italian for 'a scribbling'

The word was first used in 1851 to describe the ancient inscriptions on Pompeii's walls. "Graffiti" is the plural form of "graffito," which means "a scribbling."

Around 32% of American adults have at least one tattoo

Tattoos have waxed and waned in popularity over the centuries, depending upon the social standing of their wearers. Throughout US history, they were often considered taboo. However, growing acceptance of tattoos means they’re more visible in the public eye.

There's no right way to say 'taco'

While Americans ("tah-co") and Brits ("tack-oh") might argue about the correct pronunciation, both are understood in Spanish-speaking countries. Linguists note that the word's pronunciation is ever-evolving and informed by various cultural, psychological, and historical factors.

There are stigmas attached to tattoos

Although tattoos are fairly common in the US, some taboos remain. A 2017 study in the Journal of Social Psychology found discrimination against tattoos is alive and well, and that even individuals with tattoos associate them with negative stereotypes.

TAKI 183 was a teenager whose graffiti drew widespread attention

Inspired by graffiti he saw throughout the city—including some tags he saw as early as 1964—the 16-year-old began tagging surfaces with "TAKI 183," a reference to a Greek nickname for Demetrius and his street (183rd) in Washington Heights. After a 1971 New York Times profile, his tag—and graffiti culture in New York—exploded.

World Cup athletes use tattoos to convey aspects of their identity—including details of their faith, family, and accomplishments—in the otherwise tightly regulated arena of professional sports.

Tattoo inks are largely unregulated by the FDA

With hundreds of ink manufacturers, all unregulated by the FDA, it’s hard to determine the exact ingredients in tattoo inks. Some pigments may contain carcinogenic chemicals, such as heavy metals and aromatic hydrocarbons, or even bacterial contaminants. Red ink often causes allergic reactions and may even contain lead or mercury.

Cacao is a Maya word that survives today

In the 1980s, archaeologists finally deciphered Maya hieroglyphs in part by identifying known words. Maya scholar David Stuart notes that cacao—still used today—was one of the key linguistic anchors that unlocked ancient Maya texts.

Gutai, a Japanese form of performance art, used the body as a canvas, anticipating the Westernized version of the art form by several decades.

Nail art can be traced back to 5,000 BCE

Archaeologists discovered Egyptian mummies with nail art and henna-tinted fingertips. The trend would continue informally for centuries until Revlon introduced modern nail polish in 1932.

Yakuza gangsters' tattoos often portrayed moments from their lives

Although tattoos have been worn in Japan for centuries, no single group is more famous for their elaborate, full-body tattoos—featuring traditional Japanese art—than Yakuza gangsters. The criminal organization does not use tattoos to mark their association, though. Instead, the scenes are intensely personal.

Ancient Romans sometimes lobbed insults through graffiti

Graffiti was used to communicate ideas, offer advice, and, not unlike the internet, talk some trash. That was especially true with tourists, who sometimes scrawled messages on the pyramids, including one person who complained, "I can not read the hierogylphics." In response, someone replied, "Why do you care that you can not read the hieroglyphics? I do not understand your concern."

Laser procedures have made tattoo removal much more common

An increasing number of Americans, including high-profile celebrities, get tattoos removed because laser removal has become more advanced and cost-effective. The tattoo industry is adjusting to this mainstream trend.

Archaeologists discovered over 11,000 examples of graffiti in ancient Pompeii

Residents drew various figures and announcements on homes, temples, and walls, much of it preserved by volcanic ash. While some were clearly intended to be artistic, scholars have noted that the ancient graffiti has more in common with social media than with the tags and murals we associate today with the art form.

Tarring and feathering was a violent form of vigilante justice in Colonial America.

How the Inca used threads to communicate

One of the great mysteries of ancient Peru is that the Inca did not have a system of writing, but communicated with a system of strings tied with knots. This 4-minute video explores its possible uses.

Ancient Egyptian papyrus from 16th century BCE seems to reference tinnitus

Ancient Egyptians wrote that they treated "bewitched ear" with herbal concoctions that involved frankincense and other ingredients, which were placed in the ear.

Crowds used a thumb gesture to decide whether a gladiator lived or died

This explainer unpacks pollice verso, the hand signal spectators used to call for a gladiator’s execution. Ancient sources never specify the direction; evidence suggests that the thumb was likely turned up or thrust toward the throat, not down.