?Hidersine Cello 3C? Rosin slightly stickier than violin rosin. Comes in a tin with a cloth wrapped round it.Rosin is a natural product made from the resin secreted by fir and pine trees. The resin is heated and mixed with oil and other ingredients, then cooled and allowed to solidify in the now familiar cake form. The carefully guarded recipes vary considerably and are carefully formulated to suit different types of strings and playing styles. To use first roughen the rosin with sandpaper or something similar and then apply to your cello bow.