MILAN, Italy -- You can't always erase the mistakes of youth, especially if you want to remove a tattoo.
A new study finds larger tattoos and those that contain colors like blue and yellow are more difficult to get lasered off.
But the research also suggests tattoos are hard to remove on people who smoke. Doctors say smoking can reduce the chance of a successful removal by 70 percent.
It often takes as many as 10 laser treatments to take off most tattoos.
This study was conducted by a laser surgery center in Milan and is published in the Archives of Dermatology.