I've been playin' a lot on my razor sharp hand-tool and I have found that more is better and too much is not enough. Sometimes it causes all the bow hairs to stick together, especially during warm weather, but all I do is scrape the bow across the edge of the blade and viola!(That's a French word which means everything is ok now.) As to the comments regarding how rosin adversely affects the finish of a violin I'd like to impart this tale. After purchasing an old German violin at a junk store in New Orleans I brought it to a local repairman. I had heard he was a bit eccentric but a fine craftsman. The instrument had a great deal of build up of old rosin under the strings on the body, it was black. After I got it back from the shop all the rosin build up was gone. I was surprised because previously I had tried to remove it with no success. I asked the repairman how he did it but he would not reveal his secret. Spooky huh? Reggie