by POPSUGAR Beauty 11

Part five of my six part series on makeup brush hair is about squirrel hair. This type of hair is durable, fine, thin and has a thick belly with a fine tip — that's where it gets its conical shape. Also, it's the softest natural hair used in makeup brushes.

The type of hair that coveted for these highly sought after brushes is from the long-haired squirrel, not the typical garden variety that you see running around in your backyard, so don't worry about your chubby lil' nut-stealing friends.

Squirrel hair is ideal for blending heavy pigment, which is why it is commonly found in eye shadow crease brushes like this Professional Platinum Natural Crease Brush from Sephora ($24). Squirrel hair is also often mixed with other types of hair to bring down the cost, so if you are buying something expensive, it is important to inquire about the origin of the hairs.