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 color, 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 everyone, 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 
source:lifehacker
