They are the opaque frit or semi-raw highly lead glazes with the content of 40-70% PbO, designed entirely for the decorative ceramics.
The glazes show silky mat till rough mat surface with perceptible colour inhomogeneities („extracts“), arised by crystallization of definite component by the cooling, with it the glazes are super-saturated, as a rule of rutile (TiO2).
It is possible to reach very impressive effects in the thicker layer by the firing in horizontal position. In vertical position, the glazes flow off and at the temperatures 1040-1100°C, it is possible to use them as the flowing glazes. They are suitable for white and in color burny body with high thermal expansivity coefficient CTE (a > 70.10-7 K-1) on shorter body mass it can reach the crackle of the glaze. For theirs application, they are suitable all glazing techniques.
The final look of this glazes after the firing is depend upon lot of factors, e.g. body quality, glazing stoutness, firing temperature, kiln atmosphere, position at the firing etc…
Before the using in at more, it is necessary always to perform the test in concrete conditions at customers.