Archaeological evidence suggests that, in the non-Western world, strings for bowed instruments were made from the muscle or connective tissue of water fowl in 10th century China, and from the intestines of young lions in 9th century Arabia. Violin strings were initially made from catgut (an etymological anomaly which does not refer to the intestines of domestic felines), and by the 17th century, sheep's gut was the preferred material in Europe. From the latter half of the 17th century, the G string was frequently wound with silver to achieve a more powerful sound; this technique is thought to have been invented in Bologna, Italy.
During the 19th century, the following set-up became popular: plain gut E and A, twisted gut D and G wound with copper, silver wire or silver-plated copper. Steel increasingly replaced gut for the E string, affording greater endurance and a larger sound. During the 20th century, the twisted gut D string was gradually superseded by gut with an aluminium winding.
Steel strings were developed in the late 19th century after the proliferation of the steel E string and the development of a more elastic woven core. String-makers began to wind the A, D and G strings with an array of different metals, for example, chrome steel, silver and eventually tungsten. Metal strings have greater durability, are more quickly tuned with adjusters, and do not stretch as much; the deficiencies of metal strings include their supposed lack of tonal quality and the potentially damaging pressure which they place on the violin. The invention of metal-wound strings with a nylon or gut core addressed these problems.
Thomastik Infeld pioneered the development of synthetic strings in the 20th century, producing strings which replicated the advantages of gut, but not the disadvantages. Synthetic strings are thus more durable than gut strings and are not susceptible to changes in temperature and humidity.