 Black fittings on low-cost instruments are often made from inexpensive wood that has been blackened or "ebonized" to look like ebony, which is much harder and more expensive.Ebonised parts such as tuning pegs may crack or split, and the black surface of the fingerboard will eventually wear down to reveal the lighter wood underneath.Historically, cello strings had cores made out of catgut, which, despite its name is made from sheep or goat intestines which are dried out.