A client reacts as she is tattooed during the Tattoo Week SP 2016 in Sao Paulo, Brazil, July 23, 2016. (Photo by Paulo Whitaker/Reuters)

For more than 2,000 years, women from the Baiga tribe in the highland district of Dindori, in central India’s Madhya Pradesh state, have been tattooed. Sumintra, 25, from Bona village, has the markings across her forehead, legs and arms. The women who work as tattoo artists are knowledgable about the different types of designs and pigments preferred by various tribes, and their meanings are passed to them by their mothers. The tattooing ‘season’ begins with the approach of winter. (Photo by Ronny Sen/WaterAid/The Guardian)

Tattoo artist Tokyo Hiro draws a scorpion to be tattooed on a customer at the Tattoo the Earth Festival August 9, 2002 in Oakland, California. The Tattoo the Earth festival focuses on the tattooing culture and is the largest tattoo event of its kind. (Photo by Justin Sullivan/Getty Images)

A woman is tattooed during the Great British Tattoo Show in Alexandra Palace in north London, Britain May 23, 2015. (Photo by Neil Hall/Reuters)

Mary Jose Cristerna, a Mexican known as The Vampire Woman, poses for the public to take portraits of her during the annual Venezuela Tattoo International Expo in Caracas, Venezuela, Thursday, January 29, 2015. Tattoo artists from around the world are gathering for the four-day event that also includes under the skin implants and body piercing. (Photo by Ariana Cubillos/AP Photo)

An artist draws a tattoo on a woman's arm during a tattoo convention in Ljubljana April 18, 2015. (Photo by Srdjan Zivulovic/Reuters)

A woman with a Japanese style full back body tattoo at the 12th London International Tattoo Convention, which opened today in Tobacco Dock, east London on September 23, 2016. The show features over 400 of the world's finest, most prestigious and elite tattoo artists as well as a showcasing alternative culture in the form of piercing, burlesque and the Miss Pin Up UK competition. Around 20,000 people will attend over the weekend. (Photo by Michael Preston/Alamy Live News)