Ok so why should you wash your brushes?
1. Begin by running your brushes under lukewarm water, rinsing out all of the residual makeup. Just wet the bristles of the brush never where the handle meets the ferrule (the area between the bristles and the head) as this can loosen the glue over time.
2. Fill a bowl with lukewarm water and a squirt of shampoo, and gently swirl your brush tip in the water. If you need to, you can also swirl the brush in the palm of your hand to work up a lather. If your brushes are very dirty you may need to repeat this step.
3. Rinse the brush tip under running water once again until the water runs clear from the brush,
4. Use a cloth to wipe your brush clean, reshaping the bristles as you go.
5. Lay your brushes flat on a cloth to dry.