you hear it again and again how the simplest tools such as your brushes can change the whole vibe of your make-up application, and while others may think the shape and density are one of the more crucial criteria, the material/hair/bristle used to make the brush can also play an important element to create that pretty made-up face =}
trivia 1: Goat haired brushes give you a glossy finished look, while squirrel haired brushes give you a matte finished look.
trivia 2: Goat hair: For those with oily skin. You can expect covering effects on pores naturally as fine powder can be applied evenly over the pores. In addition, you can get lustrous shiny skin by sweeping gently with the whole surface.
Trivia 3: Blue squirrel hair: For those with dry, or sensitive skin. Blue squirrel hair is not resilient; therefore a finished look will be more matte-looking as powder is lightly applied to your skin. The hair is very delicate so it is the basic rule to use the brush surface by laying the brush down. Blue squirrel hair is suitable for loose powder application, however as the hair is very delicate, blue squirrel hair brushes are not suitable for powders containing oil.
hope this helps a bit