Epidermis structure, density, and Significance in needle selection

The epidermis, as the outermost layer of the skin, varies in thickness across different body areas. In the brow region, its thickness is approximately 0.05 to 0.1 mm. The epidermis comprises five distinct layers: Stratum Corneum, Stratum Granulosum, Stratum Spinosum, and Stratum Basale. Notably, the Stratum Lucidum is absent in the brow area. Needle Diameter vs. Epidermal Depth. Typically, the diameter of a pigmentation needle ranges from 150,000 to 300,000 nanometers (0.15 - 0.3 mm). This is significantly larger than the depth of the epidermis in the brow area, which spans only about 50,000 to 100,000 nanometers (0.05 - 0.1...