I usually use wood block rosin, but I thought I would try something new. I used it as soon as I received it, and noticed a big difference in how my bow gripped the strings, but still allowed for smooth bowing. I don't know if rosin can really make a difference, but I thought the sound was smoother and allowed me to produce greater volume. The only thing is tha it dropped it on the floor and broke. I think it should be replaced since I used it properly and had wrapped it in the cloth as intended. I am upset that I cannot get replacement, so only 2 stars.