Page 133 - Blog Posts v1

B6 - Tattoo ink colours, absorptions and fluences...
An excellent clinical report by Scheibner (
Laser.) found that the minimum fluence required to induce a good reaction from black tattoo ink, using a Q-switched ruby laser, was 2 Joules/cm2.
This threshold fluence was for black ink, which absorbs much more strongly than virtually all coloured inks. So, the question is, what are the minimum fluences required for other colours – they must be higher than for black since they absorb less energy! (I haven’t seen a good report on this – if anyone knows of one, please let me know).
To answer this question, we need to know how strongly each colour absorbs light (of various wavelengths).
Another excellent study by Choi et.al. (Effects of picosecond laser on the multi-colored tattoo removal using Hartley guinea pig: A preliminary study.) looked at the relative responses in coloured tattoo inks to three wavelengths (532, 755 and 1064nm) from both nanosecond and picosecond lasers. We can use the results from this study to give an indication of the relative absorptions of these coloured inks.
(ps – picosecond, ns – nanosecond)
The Choi study revealed some very interesting results. They found that each of the colours tested responded differently to each wavelength, to various degrees (see table above). Black ink absorbed the most energy, obviously, and reacted better with pico lasers compared with nano lasers (except with the picosecond Alexandrite 755nm wavelength).
Red ink reacted best with the 532nm wavelength, which is green, then with the infrared 1064nm wavelength, and the least with the Alex 755nm wavelength. Orange and yellow inks reacted in the same way as red.
SCHEIBNER, A., KENNY, G., WHITE, W. and
WHEELAND, R.G. (1990), A Superior Method of Tattoo Removal Using the Q-Switched Ruby
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