Ink on Stink refers to women of lesser intelligence that believe a tattoo makes them more sexy, allows them to make a statement of some kind, or is just stylish. In reality it shows their lack of intelligence and vulnerability to an impulse to distort their body without a thought to future consequences. It makes them look slutty, which is where the Stink portion of this expression comes from, since sluts frequently have stinky vaginas. Ever see a woman with a tattoo she got years before that is now indistinguishable due to older sagging skin?
A Tramp Stamp is a good example of Ink on Stink. You have to wonder how many guys have had their hands all over it as well as the rest of the bimbo's body. Some women even use tattoos to attempt to cover up stretch marks.