Background and Design: A fundamental idea of laser treatment of tattoo
s is that the wavelength must be well absorbed by the tattoo color. In
this study, absorption by different tattoo colors was therefore measu
red in vivo by skin reflectance to establish optimal laser wavelengths
for different tattoo colors. Spectral reflectance by tattooed skin an
d by normal, uninvolved skin was measured in 10-nm steps in a waveleng
th range from 300 to 800 nm on eight human volunteers with a total of
13 tattoos, which consisted of 14 different tattoo colors. Wavelength
ranges for maximal absorption were established. Results: We found that
tattoos absorbed maximally in the following ranges: red tattoos, from
505 to 560 nm (green spectrum); green tattoos, from 630 to 740 nm (re
d spectrum); and a blue-green tattoo, in two ranges from 400 to 450 nm
and from 505 to 560 nm (blue-purple and green spectrums, respectively
). Yellow tattoos absorbed maximally from 450 to 510 nm (blue-green sp
ectrum), purple tattoos absorbed maximally from 550 to 640 nm (green-y
ellow-orange-red spectrum), blue tattoos absorbed maximally from 620 t
o 730 nm (red spectrum), and orange tattoos absorbed maximally from 50
0 to 525 nm (green spectrum). Black and gray absorbed broadly in the v
isible spectrum, but these colors were most effective from 600 to 800
nm. Optimal and suboptimal laser wavelengths are proposed.Conclusion:
We recommend that wavelength ranges should be established for maximal
tattoo absorption before laser treatment of decorative tattoos to sele
ct the most optimal laser wavelength present.