Laser tattoo removal was first used in the late 1960s following the creation of the first laser, but removal often led to suboptimal results due to significant surrounding tissue destruction and scarring. It was not until the description of the theory of selective photothermolysis in the 1980s that exogenous tattoo pigment could be selectively targeted as a chromophore at specific wavelengths. According to this theory, the target chromophore must be heated quickly before it can cool. For optimal destruction, the pulse durations need to be shorter than the thermal relaxation time of the tattoo particle or the time that is required for the target to lose 50% of its heat. Due to the small size of the tattoo particles, rapid pulses of high heat at very short pulse durations in the nanosecond to picosecond range are required to prevent cooling of the particles. The thermal relaxation time of tattoo particles is thought to be less than ten nanoseconds. Lasers with Q-switched technology are capable of producing light pulses of short duration but with a peak power that is much higher than is achievable with continuous wave output. More recently, lasers of even shorter pulse duration have been developed, potentially offering better targeting of chromophores with less damage to surrounding tissue.