During the preparation of ceramic glaze suspensions it is necessary to guarantee that the suspension possesses the required properties, with several parameters having to be rigorously controlled, e.g., particle size and solids concentration. composition of the suspension and ionic charge of the liquid. This study focuses attention on the influence of particle size distribution on three important properties of glaze suspensions: rheological behavior, opacity and reflectance characteristics and tendency to dissolve. In this paper, results are presented for two glaze formulations prepared with two different commercial frits of distinct composition. The glazes were prepared in a laboratory ball mill and the grinding time was adjusted for each formulation, in order to obtain suspensions with different particle size (at least three different grinding times). The rheological behavior is strongly dependent on the particle size and also on changes in the interactions between the particles, caused by modifications in the cationic content of the suspending medium, as a result of frit dissolution, which is also influenced by the size of the particles.