How to do life casting with skin safe silicone rubber?

How to do life casting with skin safe silicone rubber? Here let me make an example for making silicone mask:

Before the production, the mold master should first apply a thin layer of Vaseline on the eyebrows and eyelashes of the models to prevent them from sticking to the silicone mask. 

Then, the mold master applied a layer of silicone on the model's face.

 In the next process, the model must be expressionless and sit still, because even slight changes in expression will directly affect the final shaping of the mask. 

After several minutes, the silicone rubber applied on the face solidified. At this time, the mold maker also needs to plaster the face of the model to shape the mask. Two hours later, the plaster was removed, and the molded silicone facial mask also appeared. 

The mold maker only needs to sew eyebrows and eyelashes on the silicone facial mask and dye the skin color, and a lifelike mask is born.