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
Trembita Musical Instrument Factory 19 instruments were made. These instruments were diatonically tuned with 34 strings, however they did not have sufficient volume and did not allow the player to play in different keys easily. Continual serial manufacture of banduras was set up in 1964. Vasyl Herasymenko developed an acceptable model instrument and also developed a serial process for the mass production of banduras. From 1964-68 some 300 experimental instruments were produced. These instruments became known as the "Lviviankas" . The first models had 58 strings which included 17 bass strings. This particular instrument differed from counterparts made at the Chernihiv Musical Instruments Factory