I bought a Holstein Yellow Sandalwood bow a few months ago for the kid's big Kore K501 violin. The bow sounded absolutely mediocre on that violin. We thought maybe the yellow sandalwood was just so so.... This evening, however, we got a nice surprise! We upgraded to an Eastman Albert Nebel VL601, but didn't want to buy a K. Holtz fiberglass bow that typically comes with an Eastman violin. Out of necessity, the Holstein Yellow Sandalwood Bow was used for the test-drive period. My goodness, the Holstein bow came alive! Or should I say the Nebel violin came alive? Or more accurately both things came alive? They were like a match in heaven and have been awaiting forever for each other! The sounds they make together are incredibly sweet, smooth, and mellow!!  Turns out this Holstein bow is a very good bow! But how do we explain why it sounds mediocre on one violin, but works like a charm on another?