6. Most tattoo ink is not vegan

Nowadays you can find vegan tattoo shops that only use ink that doesn’t contain any animal byproducts, but don’t just assume the parlor you go to is vegan. In fact, tattoo ink is commonly made out of the charred bones and the fat of dead animals. So if you’re a vegan or a vegetarian, you may have just found out that you weren’t as loyal to your lifestyle choice as you thought you were.

7. Many people are allergic to color ink

Color tattoos can be much more difficult for people to handle than black and gray tattoos. Ingredients such as iron oxide, mercury sulfide and cadmium sulfide are often contained in color pigments, and any of these can cause an allergic reaction in a person’s skin. Beware the color red, especially, since it is the color most associated with allergic reactions.

8. Tattoos date back at least 5,000 years

The oldest record (so far) of a tattooed person is Ötzi the Iceman, who has been scientifically dated to 3250 B.C. He and his 61 tattoos were found buried under a glacier in Europe, and both have been studied meticulously since their discovery. So next time someone says something snide about tattoos, tell them that it is one of the world’s most ancient artforms.

9. The tattoo gun is not the only tool used for tattooing

Bamboo torture is known as one of the most painful and horrific methods of torture in history. While this torture method works by letting bamboo grow at its naturally rapid pace and allowing it to pierce through a prisoner’s body, some would say there is another kind of bamboo torture that is also extremely painful: Bamboo needle tattooing. Instead of using a mechanized tattoo gun like most tattoo shops use today, some artists in various parts of the world rely on a bamboo needle to insert the ink into a person’s skin, one dot at a time. Raking and striking is another tattoo method, which is kind of like using a tiny hammer and chisel to insert ink into the skin. Fun, right?

10. Women find tattooed men more attractive, according to research

A recent study that was published in the journal Personality And Individual Differences found that women see men with tattoos as more masculine, dominant and healthy. Women also tend to think that a tattooed man is more of a risk-taker, which to some may be an undesirable quality, but to others is incredibly attractive.