Tattoos are certainly not for everyone, but if you're considering one, make sure you know what you're getting into. This pain chart highlights the parts of the body that can hurt the most when the needle comes down.
Getting a tattoo will hurt; there's no way around that. However, some parts of the body are extremely sensitive to pain, and only the bravest of brave should even consider tattoos in those zones. This pain chart from Tattoos-Hurt.com explains it all using colour, with yellow being the least painful to purple being excruciatingly painful. It's not surprising that the most painful areas are also considered the most vulnerable areas of the body.
For a general rule, if you're extremely ticklish in an area, it will probably hurt really bad to have it tattooed. An important thing to consider, however, is the fact that everyone has different thresholds for pain. This chart won't be spot on for every individual, but it is still effective at giving you a general idea for choosing a location. Just make sure you pick something you really love, or you might end up wanting to cover it up.
Tattoo Pain Scale [Tattoos Hurt]