One remains astonished by the simplicity of the tools used to build the moulds of the bells. The moulding material has been the same for centuries, as has the use of templates. For the past 30 years, however, the profile of each bell has been modelled on a computer and then reproduced on laser-cut wooden or brass plates. The templates of the future bell’s interior and exterior are mounted on a pin and are used as guides in the construction of the different parts of the mould. This moulding technique is said ‘au trousseau’.