Strings (tennis) be more durable than many other types of strings due to its outstanding tension retention. This may help to offset the high initial cost. The use of a dense string pattern also generally improves the longevity of natural gut. Natural gut is produced by drying fibers extracted from a part of the cow intestine called the serous membrane, or serosa, which contains collagen designed to withstand the stretching and contraction of the intestine. It is this elasticity that makes the fibers useful for tennis string. Sheep intestines have also been used for racquet strings in the past. The first natural
Kingri (string instrument) inserted into the fingerboard with three pegs. The strings on the bow are made by using three tufts of horse hair or Goongaru. The strings on the instrument were originally made of animal gut, but modern day Indian gypsies typically use low quality steel strings instead, resulting in more vibrato and lending the instrument a sound similar to the violin. Sri Lankan composer Dinesh Subasinghe used the kingri on the album Rawan Nada as well as for performing folk music. In 2007, Subasinghe made some modifications to the instrument and discovered it to be another close version of the Ravanstron