Cello 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. Most modern strings used in the 2010s are wound with metallic materials like aluminum, titanium and chromium. Cellists may mix different types of strings on their instruments. The pitches of
Guqin strings silk and also they were louder and more stable. A set could last many years and not break. The only drawback for traditionalists was that the strings had a harsh metallic sound which was considered inelegant. Another factor was that the strings could eventually wear the lacquer out requiring the qin surface to be repaired more often. Around 2007, a new set of strings were produced made of mostly a nylon core coiled with nylon like the metal-nylon strings, possibly in imitation of Western catgut strings. The sound is similar to the metal-nylon strings but without the metallic tone to