Rotosound Music Strings are all manufactured in-house on machines that were originally designed by James How in the 1960s. The materials used have been kept to the original specification ensuring that Rotosound Music Strings keep that unique tone that sets them apart from other brands. Bass string manufacturing is highly skilled and although automated processes are a part of our whole operation certain bass guitar strings are made by hand, and those string makers are proud of the product that they produce. To maintain this quality within the company's organisation is a three stage finite quality control process which has been in place for many years. This eliminates imperfect product and insures that you the musician, get a great sounding string !