Four fluxing agents (aq. solns.) were added (0.1-0.6%) to a usual ceramic mass consisting of stone-quartz dlour, glass sand, 4 clays and 3 caolins. The fluxed masses were studied for thixotropy and structural rigidity and then used for prepg. ceramic test samples by drying and burning at 1200 degrees C. The samples were studied for shrinkage and flexural (bending) strength after drying and after burning, for water intake and phase compn. (glass, quartz, mullite, pores). The samples made of the masses fluxed with alkali metal silicates (0.25%), a polymeric Na carboxylate (0.13%) and org. polyelectrolytes (0.15%) showed the highest technolog. quality.