http://flippednormals.com/downloads/handpainting-skin-textures-in-substance-painter/

In this Substance Painter tutorial, you’ll learn everything you need in order to paint realistic human skin from scratch. We use very easy techniques which everyone can use. The series starts off by laying down a quick base with only a few colors, which are then refined as we progress. We’ll also cover how to paint roughness and bump maps, to greatly increase realism.  COLOR THEORY FOR SKIN We cover the fundamentals of color theory when it comes to skin. Once you understand how to use a few simple colors to paint stunning skin textures, you can paint any kind of organic textures, from humans to killer aliens! We believe in simplicity and we keep everything nice and clear for all skill levels.  USED BY THE PROFESSIONALS The techniques taught have been used by your instructors to paint detailed texture maps for Hollywood movies, such as Pacific Rim 2 and Batman V Superman. Not only are the techniques easy to use, they are also incredibly powerful. You can use what you learn on anything from personal projects to giant blockbusters!