How to clean a brush that has dried hard with acrylic paint
by Geraldine O'Hare
(UK)
Soak in acetone. When brush is starting to soften gently coax the bristles apart with a pointed object such as a darning needle. Soak again and repeat as many times as you find necessary. When all paint has been removed, wash in warm soapy water and dry. The brush will be like new again!