D’Addario Natural Bow Rosin All-natural ingredients are combined to create D’Addario Natural Rosin, perfect for either horsehair or synthetic hair bows. Its unique plastic channel provides an easy grip for students and is packaged to fit nicely into instrument cases. D’Addario Natural Rosin offers premium performance at a great value. All natural ingredients Plastic channel provides easy grip Suitable for horsehair or synthetic hair bows Designed and manufactured in the USA at our New York facility to the most stringent quality controls in the industry