As growing numbers of people rue the tattoos they got in their youth, a new study has found that tattoo removal is less likely to succeed if the person is a smoker, the design contains colors such as blue or yellow and is larger than 12 inches.

The study is believed to be the first research that looked at several factors—which included tattoo size and location on the body—involved with successful tattoo removal, according to the researchers.

The standard procedure for removing tattoos currently is treatment with a laser called a Q-switched laser, or QSL, applied over a number of sessions. But the technique can lose its effectiveness depending on certain variables, according to the study, published online on Monday in the American Medical Association's Archives of Dermatology.

Smoking, for instance, can reduce by 70% the chance of successfully removing a tattoo after 10 treatment sessions.

Dermatologists have long known certain colors are easier to remove than others, but the findings on the impact of smoking on tattoo removal are new.