Ceramic - Pottery Dictionary

by Susan Mussi

GLAZE-BASE (b) Types of bases

ca: ESMALT-BASE (b) Tipus de bases

es: ESMALTE-BASE (b) Tipos de bases

Tin oxide is the main ingredient of glazes-bases and is used for its whiteness and opacity. There are many different types of glaze-base, made up with different formulas and textures, matte, semi-matte and crackle, etc that can be applied onto ware in different ways and that vitrify at different temperatures and all can be purchased ready-made. When bought, it is in powder form, then mixed with water and laid over tiles, plates and jars that have been bisque fired. Application in both methods can be made by spraying, painting, burnishing, dipping, pouring, etc., depending on your desired results and the thickness of the glaze is determined by the amount of water added and needed. A glaze that has an off-white tone helps to achieve an antique look.

The methods used will depend on the type of clay the bisque is made of and to what temperature it can be fired. In the case of red clay, glazes can be used that mature up to 1100º C, and if refractory, they can reach 1300º C. Ones that vitrify at different temperatures can be added to the same design, always firing at the same or lower temperature than the lowest used, never higher.

Glaze-bases: There is a great selection of glaze-bases that can be purchased already prepared in the form of powder. In shops that specialize in ceramics most products can be bought in small or in large quantities in sacks of 25kl.


Glaze Crackle: glaze-base prepared to leave a crazed surface after being fired.
Glaze White: a strong white, has a very industrial appearance and a strong glaze finish-
Glaze Semi-Matte: white with a soft glaze finish. Glaze Siglo 18 (Spanish for 18th Century) It is the one I prefer as it has an off white color which helps to give an antique look.
Glaze Matte: without any shine.

a) The glaze-base we use when working with the Majolica method in Spain leaves a surface that has an off white color which helps to give an antique look. It is called “Siglo 18” (Spanish for 18th Century)
b) Glazes or glaze colors, which have foreign bodies to form textures, cannot be sieved, as this would separate them from the glaze, crackle is a good example.

The following sections go through the process of preparing the glaze and putting it onto tiles, plates, jars and lids. These sections and the videos are linked together in the order of working.
This is the first; Glaze-base (c) Preparing the glaze-base