Rib tattoos are dank. I have one on the left side of my ribs, and was told RIGHT before I got it by the artist to consider another spot, because ribs are painful. He was covered in tats, and said that he'd gotten a rib tattoo that made his eyes water, and it was agony.
Mine didn't hurt at all at the beginning, really. Felt like what I'd imagine any tattoo feels like, which isn't pleasant, but not really painful, per say. Then, he had to start really filling in the outline, parts of which were between ribs and just under the bottom of my ribcage, and that was pretty painful, but in a weird way. It was a lot sharper and more pinching pain than the parts that were just on the bone, which kind of hurt a little, but the real uncomfortable bit was the sharp pains that radiated down to my hip bone.
My tattoo was a birthday present from my parents (weird, I know
) and my dad seemed to be taking the pain a lot worse than me, even though he was just getting a small forearm piece...but keep in mind that although it's not *too* bad, the ribs are pretty damn sensitive.
I remember that about 24 hours after the tattoo, the entire side hurt kind of in the way that I did when I had bruised ribs (I guess the vibration against the bones irritated them) but about 48 hours later, didn't hurt at all.