Finally, a way to clean and preserve brushes easily and inexpensively. Unique hard cake form - just add water, work into a lather, and brushes come clean. works on oil, acrylic, or watercolour, and won’t harm red sable or any type of bristle brush. Restores old, hardened brushes even after days, weeks or years! Also removes petroleum-based products. By using this product you can extend the life of your brushes.