Kafka Design Brush Oil is a 15 degree Peacock Neatsfoot oil that is refined to have no acids or wax. This nurtures brush hair and preserves the natural quality. It is scented mildly with patchouli oil to give a more pleasant smell. This is the only oil that should ever touch a brush. Contains no petroleum. For the sake of your brushes do not use mineral oil (baby oil) or any automotive oils or transmission fluid. They are not a natural fluid for brush hair.