What Is Rosin?

Bow rosin is made of tree sap combined with small amounts of other ingredients (or not), poured into molds, allowed to dry and harden, unmolded, and polished.

Why rosin a bow?

Without rosin, the hair is too smooth; it slides over the strings and the sound is faint and thin. When bow hair is filled with the right amount of rosin, the rosin particles “bite” or micro-pluck the strings, causing them to vibrate and create a beautiful tone.

When to Get Professional Help...

For your bow

• Because playing eventually wears out the hair, your bow should be professionally rehaired at least once each year, and any time the hair has lost its bite (friction), is dirty and can’t be cleaned well enough, or has lost a lot of hair.

• Dirty bow hair can be cleaned with denatured alcohol, but alcohol can damage the finish of the stick, so it’s safer to have your luthier clean it.

• If the ivory or bone tip on the bow's head cracks or breaks, have your luthier replace it.

• If the bow’s winding and leather grip are worn or missing, have them replaced.

• If turning the bow screw slowly in a clockwise direction fails to tighten the hair, your bow screw eyelet will need to be replaced.

• If for any reason the curve of the bow stick has been lost or distorted, take it to your luthier; the proper shape can be restored.

• If your bow breaks, take it to your luthier to see if the bow can be repaired so that it is playable, although it will lose some of its value.

Extreme Enemies

Humidity and temperature extremes are your enemies because they can ruin your bow and instrument.

• Both bow hair and wood stretch and expand in high humidity and shrink in low humidity. It’s important to keep your instrument and bow in neutral humidity, as much as possible. The best way to do this is to keep them in the case when you’re not playing.

• Bow and instrument varnish can be melt in hot temperature or in direct sunlight, even when it’s not that hot outside. Never leave your bow or instrument in a car (whether it’s hot or cold outside) or in direct sunlight.

• Wood can contract and crack in low temperature.

• Humidity and temperature extremes can have even worse effects on a bow if the hair has not been loosened. If tightened hair shrinks, it can warp or break the bow stick. Always loosen the hair when you’re through playing.

Protect Your Bow and Instrument

Your bow and instrument are delicate; handle them accordingly. Train yourself to be conscious of where the bow and instrument are and how you are handling them when they are outside the case.

• When you’re carrying either one, hold it firmly and keep it close to you; don’t bang it on things.

• Never leave a bow or instrument on the floor (it could be stepped on) or where they could be knocked off and land on the floor.

• Never  leave one of them on furniture, where someone might accidentally sit on it.

• Don’t ever  applaud by tapping your bow on the stand. That’s a “good” way to break a bow.

• Don’t touch the bow hair! (The naturally occurring oil on your fingers can make the hair unable to take up rosin, and then you might have to have it re-haired.)

• Never use any chemicals or other liquids to clean the bow or instrument; they could damage it.

Bow Bugs!

Bow bugs, also known as carpet beetles and bow mites, can be members of several species of the Dermestidae family, in the larval stage. They’re fairly common, even in scrupulously clean homes, and they love to eat bow hair as well as wool. If your bow hair is getting brittle or breaking in the middle, bow bugs have infested your case. If your case has bow bugs, you will need to have the bow rehaired professionally, and you or the luthier will need to clean and disinfect your case. Then you should follow some easy steps to ensure that they don’t come back.

It is important not to store your bow in an unopened case for long periods of time, because bow bugs do best in dark, enclosed places.