1. Color
Disposable black masks are very easy to distinguish between the inside and the outside, which can be judged by the color. Generally, the inner layer of the black mask is white and the outer layer is white.
2. Folds
Secondly, the folds can also be separated from the inside and outside of the black mask. The fold opening of the outer layer of the black mask is downward, and the inner layer is upward.
3. Material
The second is the material. The outer layer of the disposable black mask is made of hydrophobic material, which is smooth to the touch, while the inner layer is made of skin-friendly material, which is soft and comfortable. You can judge the inside and out by touching the material.
