Acrylic paints offer an extensive variety of hues in an easy-to-use form. Diluted with water instead of solvent and quick-drying, acrylics are useful for most painting projects. Unfortunately, the same quick-drying aspect can be detrimental to your brushes. If allowed to dry on paintbrush bristles, acrylic paint is difficult to remove without ruining the brushes in the process. But there is a way to clean and salvage your paintbrushes. You can remove the paint using acetone and restore the usefulness of your brush.
Place a thin plastic sheet onto a flat work surface. Open any windows and doors to ventilate the area to prevent inhaling toxic fumes from the cleaning solution.
Pour a one-inch diameter circle of acetone onto the plastic.
Swipe the dirty paintbrush through the acetone pool on the plastic. Continue to draw the brush through the acetone, covering both sides, for about two minutes. The acetone will dissolve some of the dried paint on the bristles.
Rinse the brush in a jar of water to remove the dissolved paint and free some of the bristles. Swipe the brush through the acetone again, pouring a new circle if the acetone becomes saturated with paint. Change the water periodically to prevent dragging the paint in the water back to the plastic.
Continue cleaning the brush until the acetone runs clear of paint from the bristles. Rinse the bristles in clean water and blot the brush dry.
Use synthetic brushes with acrylic paint when possible to minimize paint adherence to brush fibers.
The longer you allow the dried paint to remain on the brush, the less chance you have to salvage the brush fibers.