With summer's hot days comes more bared skin, and more opportunity for people to show off their tattoos.
From ritualistic to decorative, tattoos have been around for more than 5,000 years. As one would hope, tattooing techniques have evolved in that time. Yet surprisingly, the ink itself has not changed that much over the past few decades. A solid pigment is suspended in a liquid carrier, which could include any one or some combination of the following: water; witch hazel; alcohols, varying from ethanol to vodka to Listerine; and surfactants, such as glycerin or propylene glycol. When the needle hits the skin, the pigment is injected into the dermis, where it resides in perpetuity.
Though states regulate the sanitation of tattoo parlors, the Food & Drug Administration doesn’t monitor the actual pigments used in tattooing, which means there’s a dearth of information about what exactly you are putting into your body. Many artists simply buy ink from a commercial distributor and possibly dilute it with water or white ink for artistic effect. Still others, the more “old school” ilk, buy pigments themselves and mix them with carriers to create their own special ink.
The pigments can vary widely from minerals to industrial organics to plastic-based pigments. For example, black inks can be made from iron oxides or carbon, while blues often contain copper salts or cobalt oxides. Meanwhile, white can be achieved with titanium dioxide, zinc oxide, or lead carbonate.
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Excerpted with permission, Chemical & Engineering News
Copyright © 2007 American Chemical Society