Tattoo Removal
a research blog

Tattoo Pigment Absorption Spectra During Laser Removal

Research carried out at San Diego's Naval Medical Center investigated variance in absorption spectra of different color inks. They also investigated the corrolative effects of iron and titanium in pigments. The extent of light absorption is important in removing tattoos by laser light. High absorption in brief duration is best as it destroys the ink while leaving the surrounding skin less damaged; low absorption spread out across a longer time period will lead to skin damage and little tattoo removal.

The researchers used Q-switched laser lights at 532nm and 752nm applied to 28 tattoo pigments in an agar medium. Results were analyzed with a spectrophotometer (a device that measures light intensity at different wavelenghts, i.e., colors).

They concluded that for the red wavelength, the highest absorption was in its comlementary*; for orange, yellow and blue the highest absorption was in the adjecent colors. Green showed a great variability. Those tattoo ink pigments which contained iron showed darkening, except for black pigment. Those pigments containing titanium showed variable results.

*On a color wheel, complementary colors are those on the opposite side of the circle.

Correct light setting for tattoo removal