This International Standard establishes the graphical presentation of the complex modulus of viscoelastic vibration damping materials which are macroscopically homogeneous, linear and thermorheologically simple. The complex modulus may be the shear modulus, Young’s modulus, bulk modulus, longitudinal wave propagation modulus, or Lame modulus. This graphical presentation is convenient and sufficiently accurate for many vibration damping materials. The preferred nomenclature (parameters, symbols and definitions) is also given. The primary purpose of this International Standard is to improve communication among the diverse technological fields concerned with vibration damping materials.