* "Make-up brushes can accumulate bacteria, dust and dirt, all of which permit the growth of further bacteria. This can aggravate underlying skin conditions like acne," Manhattan dermatologist Julie Karen, M.D. states.
* Sonia Kashuk explains that creams left to dry can stiffen the bristles and affect the suppleness of natural hairs.
* If your brushes aren't clean, you will not get the true colour showing up on your face.