The bow of the violin is made of horsetail hair and has a smooth texture. The strings of the violin are made of fiber or metal and have a smooth texture. The principle of violin sounding relies on vibration, and the generation of vibration depends on friction. However, how can the two vibrating objects meet at the junction of the two smooth objects? Then you need rosin.
The rosin looks like a large piece on the outside, but in fact the effect is a small grain and a small grain. Applying rosin makes the bow hair no longer brilliance, but the surface is uneven (unobservable by the naked eye), so that the friction between the bow and the string increases, and naturally there is sound.
How to apply rosin: directly put the rosin on the bow hair, and lick it back and forth on the whole piece of bow hair. If it is a new bow, it should be rubbed for a little longer; you can also break the rosin into a part and put that part Grind into powder and apply to the bow.
Edit by Height Musical Instrument News Department