Made from a blend of soft lynx hair and red fox hair, smooth and resilient, it holds powder well and blends color beautifully, very soft on your skin. This brush has short, slightly rounded hair, good for applying gel liner in the crease of your eyes. The small shape of this brush offers precise definition, can be used to line and smudge around the lash line. Size: whole length 137 mm; hair length 7 mm; hair width 6 mm. Please allow about 1 mm error due to manual measurement. Method 1: Burn it, if it smells like we burn human hair, then it is natural hair; if it smells like we burn plastic, then it is synthetic hair. Method 2: Wash it, after dry, the synthetic hair will be almost the same as before, but the natural hair will get fluffy if you don't shape it. Tips: If you don't want the natural hair to be too fluffy, please wrap it with facial tissue after wash, and also for big brush, you could use the brush guard net that we send to shape it. For our natural hair brushes, although we have tried to deal with it, but they still have a little natural animal hair smell, and it will fade away timely, please consider if you could accept it or not, also you could use a little Comfort to wash it and cover the smell. Clean your brush before using it the first time. For daily cleaning routine, consider using a mild brush cleaner. Use the following method to keep your brush clean. We recommend weekly cleaning. 1. Use the warm running water, (being careful not to fully immerse the base of the bristles) to get rid of as much product as possible. Try using your fingers to get rid of any bits lodged toward the base of the brush head. 2. Place a pea-sized drop of brush cleanser(or any mild cleanser like baby shampoo) in the palm of your hand. 3. Swirl the bristles in the cleanser in a circular motion until the brush is fully lathered. 4. Rinse the bristles, squeezing from the base to the tips to remove excess water. 5. Repeat until the water runs clear and all makeup is removed from the brush. 6. Reshape the bristles to their original form and then use a lint-free cloth to dry each of the brushes, or you can let them air dry and place them on a cloth. You can also gently brush bristles on paper towel to remove buildup. Or you can use the brush protective net to keep the brush shape when the brush is almost dry. Tip: Wash brushes at night so they are dry and ready for use in the morning.