A detailed study of the magnetic behaviour of CrO₂ dispersions is described. The study includes static and dynamic measurements and also some preliminary results on the structure of the dispersion obtained by Neutron Depolarisation which was carried out in an attempt to determine the long-range order in the dispersion. The measurements are interpreted in terms of a simple model of the evolution of dispersion quality during the milling process. Magnetic measurements are shown to be useful in characterising dispersion quality although a number of techniques are required in order to probe different aspects of dispersion behaviour.