No discussion of the double bass is complete without mentioning the development of strings.

Around 1660 in Bologna, the wound string was invented. At the time, strings were not made of steel as they commonly are today. Instead, musicians used gut strings, which were produced by drying and twisting animal intestines—traditionally sheep, though modern gut strings may also use cattle intestines.

Pure gut strings had limitations in both thickness and tension, which made producing low pitches difficult without dramatically increasing string length. The invention of wound strings allowed makers to maintain lower pitches without excessively enlarging the instrument or its vibrating string length, representing a crucial technological development in bass design.