Figure 4 The Masson results in groups with different picosecond laser energy levels: (A) 1.1 mJ/μbeam, (B) 1.9 mJ/μbeam, (C) 2.5 mJ/μbeam, (D) 2.9 mJ/μbeam, and (E) control group. The penetration depth of the picosecond laser is different due to different energy parameters. The figure shows that the light penetration depth of 1.9 mJ/μbeam energy value (B) is the deepest, so its tattoo removal effect is better than others.