Musical strings are superficially considered simple constructions, usually built by a core of gut, synthetic fibres or a metal wire, often additionally wounded with metal wire. The pitch or fundamental frequency of a string is a function of the free vibrating length, called mensur, the tension of the string, typically defined by the instrument, the mass per unit length of the string and the string diameter. To tune a string to the desired pitch at an instrument with predefined mensur and tension requires therefore beside of a proper tensile strength of the core material a well adjusted construction. The properties of the selected materials are here of course essential. However also the most well adjusted physical construction does not guarantee a high tone quality, called timbre. A tone is formed by its fundamental frequency and the overtones of this frequency including harmonics and partials. Timbre includes the spectrum of all these frequencies and the envelope. Where spectrum means the frequencies structure of a tone, envelope describes the overall amplitude structure. Far from all overtones and amplitudes are harmonic for the listener. The art in musical string manufacturing is therefore to develop strings with an optimal timbre aligned to the actual instrument and even individual playing characteristics. And that’s no small thing. The key parameter is the right degree of internal friction of the string, called damping. One aim is to lower the amplitude of disturbing overtones or even completely to delete them. The other is to control the envelope, here especially sustain. To adjust the damping of a string, polymer chemistry in form of surface treatment, coatings and glues is applied. The right understanding of synthesis, application and behaviour of these polymeric materials and processes is therefore of essential importance.