This document specifies a method for the determination of soiling material, e.g. from previous processes, non-dispersed paint particles and other foreign material in the electro-deposition coating material. It is applicable to electro-deposition coatings for automotive industries and other general industrial applications, e.g. chiller units, consumer products, radiators, aerospace, agriculture. In practice, increased sieve residue can have different causes, such as metal particles, which are introduced together with the object to be coated, or clots.