Cork grease is a lubricant for woodwind and reed instruments such as saxophones, clarinets, bassoons, and oboes.
Cork grease is used on these seals to ease and lubricate instrument assembly, avoiding damage to the cork and the instrument's barrel.
Cork grease also acts as a preservative, keeping the wooden cork moist and thick, in turn ensuring a good seal between parts of the instrument so that no air may leak through the joints upon playing.
Cork grease can help woodwind players adjust their instruments' tuning pieces (e.g. barrels, necks, bocals, staples) in respect to their pitch.
[citation needed] In the past it was made from animal fat.