Violin bow strings are typically made of horsehair. A single violin bow will use between 160 and 180 individual hairs, which are "dressed" multiple times to ensure they are of the best quality, without kinked or thick hairs. The horsehair is found in a variety of shades from white through gray and finally black, but most bows used for violins are white or gray. This is because black hair is more coarse, it grabs hold of the strings more, and is therefore best for lower-register instruments like the bass. The horsehair is stretched into a thin ribbon, applied with rosin, and drawn across the strings to set the strings in vibration.