Also known as Microstroking, 3D Hairstroke Brows, and Eyebrow Embroidery, this manual method of micro-pigmentation has recently become all the rage (and for good reason) world wide.
This is quite a special technique of permanent cosmetic tattoo and takes endless hours of ongoing practice to perfect. A good Permanent Cosmetic Artist practicing Microblading has a keen eye and steady hand, plus a deep understanding of color theory.
Some artists promote Microblading as "semi-permanent" since this technique requires touchups between twelve and eighteen months. It is "permanent" implantation of pigment into the skin. It is not as long lasting as the powder brow tattoo procedure done with a tattoo machine since the manual tool used does not implant pigment in the same fashion.
So, whether you need a slight arch, to fill brow hair gaps, or a total reconstruction, research your potential artist well. Check for proper credentials and certifications. Be sure you are going to a Board of Health permitted establishment and love your brows!