Before applying rosin, tighten the bow hairs by gently turning the tension screw. Avoid making the bow hairs too taut---the separation between the bow stick and hair should be about the width of a pencil.
Place the bow hairs flat on the rosin at the "frog" of the bow (near the bottom where the tension screw is), and gently rub the bow hairs up and down a few times as if scrubbing a small spot on the floor.
Then, draw the bow hairs straight across the rosin until the tip of the bow is reached. Repeat the same gentle scrubbing motion at the tip of the bow, and pull the flat bow hairs back to the frog again.
Repeat this process across the full length of the bow several times.
After each playing session, use a soft, dry cloth to remove rosin dust from the strings and body of the instrument.
There aren't specific requirements for how often or how long to rosin a bow, but there is a simple test to determine if the bow has enough rosin: using the back of your thumbnail, pull it sideways across the hair of the bow, under the bow hair, near the frog.
If a small puff of rosin can be seen, the bow has enough rosin. Never use your fingers to test if the bow has enough rosin or the natural oil from your fingers will get on the hair of the bow and cause the bow to slide even more.
Too much rosin can produce a raspy, scratching sound, and can result in rosin caking the strings.
Visit our Instrument Care section for tips on how to properly take care of your bow.