The collections at the Musée de la musique in Paris include several hundred brass, silver and silver-plated wind instruments that are often exhibited, loaned or played. For the museum’s opening in1997, special mountings were proposed and designed by Franck Hammoutène and various types of thread were used to hold the instruments by their cylindrical parts. These threads were regularly untied and re-tied, for instance, for loans to temporary exhibitions, studies and when the galleries were refurbished in 2009. They were also used for temporary reinforcement (instead of adhesives), mounting (sometimes in combination with foams) and for attaching labels. Various types of thread were used – rope, fishing line and sewing thread composed of nylon, polyester, polyamide or polyethylene. The choice between these four materials depended on criteria such as the weight and nature of the instrument, colour of the surface it is attached to and the friction or tractive forces involved in the instrument’s use. Over the years, various types of surface damage to the metallic instruments have been noticed, including mechanical damage, such as scratches, and chemical damage, such as localised corrosion. After a short description of the collection of instruments and the degradation observed, this paper discusses the solutions now being applied at the Musée de la musique. The research addresses four points: 1) identification of the mechanical and chemical damage observed using visual and microscopic observations and XRF in situ; 2) the required specifications for choosing a new type of thread; 3) the types of plastic thread chosen and their various chemical and physical characteristics; and 4) corrosion tests in a humid chamber and Oddy tests with metallic sheets in contact with various types of plastic thread. The new solutions found will be introduced into the framework of the museum’s global preventive conservation protocol.