SMP Turned Blue
https://healthell.blogspot.com/2021/09/smp-turned-blue.html
This man had Scalp Micropigmentation done up to his hairline. The operator used a dark black ink that turned blue and placed it inside a very thin hairline so close to the leading edge of the hairline that the blue ink stands out.
from BaldingBlog - Hair Loss Info https://ift.tt/3AviKgV