Weasel hair is smooth and resilient, it is good at picking up desired amount of product, and very soft on your skin. A flat brush with angled hair shape design, offers easy control for applying foundation products, to create a smooth, flawless, even finish. Use to apply, distribute and blend foundation into all areas of the face. Features raw lacquer handle with copper ferrule, looks gorgeous and luxury. Size: whole length 140 mm; hair length 10-18 mm; hair width 20 mm; hair thickness 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.