Kolstein’s Ultra Formulation Rosin for cello and bass is crafted for professional musicians seeking consistent performance, smooth bowing, and minimal powdering. Cello rosin is available in medium and normal grades, providing strong, even adherence and long-lasting power, while bass rosin comes in soft, hard, and all-weather grades to suit personal preference and varying climates. Both are made from the finest ingredients, hand-poured into alloy-lined molds, cured for optimal texture, and thoughtfully packaged to maintain freshness and prevent melting. With a continual wetting action that avoids crystallization, these rosins deliver reliable application and a rich, textured sound, trusted by soloists, orchestral musicians, and recording artists worldwide.