O.K., I'll have to add my two cents worth. You need a lot to rosin. Yes it does build up on the strings. For over 40 years now I have cleaned it off the strings with a dime. Just rub it gentley over each string. You then get to clean it off the violin. If you leaave it on there for a long time it will damanage the finish. Any music store will sell you a poish that will take the excess off and polish it also. Here's story to top all rosin stories. A friend brought her violin to me and said it would not play. I took it home and tried it, she was right it did not play. Dig out the rosin, rosin the bow. That should have solved it all but it didn't play. I tried the bow on my violin (just a little ( thank goodness) no sound. The instrumnent repair man came to the high school and I talked to him he took it to the store. The piece of stuff I thought was rosin was a high class bar of furniture polish! What a mess, new strings , new hair $60 dollar epair job. Dumb mistake! bet