Larsen Viola Rosin is a medium grade rosin formulated specifically for viola. Larsen Viola Rosin's special formula is melted in a vacuum which is totally free of oxygen eliminating most of the allergens otherwise found in rosin for stringed instruments. All of the raw materials used to make this popular rosin are natural and distilled without the use of harsh chemicals that can subsequently attack bow hair. Larsen Viola Rosin is a natural product containing no harmful substances.