This document specifies a method for determining the mass portion in per cent (%) of a sprayed coating powder which is deposited on a test item under known spray gun and environmental conditions. The method is applicable to powders applied by corona or tribo charging and may be used to compare the deposition efficiency of different powders with the same or different gun with the same powder. This method should only be used for comparison when powders or guns are evaluated consecutively, as the influence of the environment and the equipment can vary significantly with time and location.