Why do people want a semi-permanent tattoo anyway? Why is this idea so popular? Because they dont like commitment! Over 40% of American marriages end in divorce and sometimes you have to live with a tattoo longer than your spouse! So, it is easy to see why the idea of a tattoo with a short commitment would be appealing to many. Change your mind? No problem! In a few months itll be gone anyway!
The fact is, when you insert tattoo ink under the skin, it's there to stay. It may fade over time, but it won't just disappear. There is no magical ink that fades completely away after a predetermined length of time.
Some of them will say that they tattoo the ink so lightly that it doesn't become permanent - that somehow it's only embedded in a temporary layer of skin that will wash it away. This is also impossible. There are 3 main layers of epidermis - most tattoos go into the second layer. But if you only go into the first layer (which would require surgical if not magical precision) the ink may very well fade - but not evenly and not completely. What you'd be left with is a really crappy half-tattoo with splotches of ink here and there.
Klicks Tattoo quotes an article from The Times where Dr. Arthur Morris, a plastic surgeon, says, "A tattoo only lasts if it goes into the dermis [the layer of cells below the epidermis]. In other words, there is no possible middle ground." In the same article, Lal Hardy, a secretery for the A.P.T., is quoted as saying, "Professional tattoo studios won't go near these so-called temporary tattoos. It is hairdressers and market stalls who are doing them. The people doing it may even believe the tattoos are temporary, but those getting them are guinea pigs."
So, basically, this is nothing but a scam. Stick-on tattoos are temporary (3-7 days) and henna art is temporary (2-4 weeks) and tattoos are permanent. Those are the only real choices you have. If you are not prepared to keep your tattoo for the rest of your life, you'd be best off not to get one at all.