Nonvitreous has a porosity of up to 20% and is used to produce wall tiles. Nonvitreous is always glazed. producing a completely hygienic surface. It is manufactured using clays. quartzes and limestone. Its low specific weight makes it ideal for wall tiles. Easy drilling and cutting are further merits of this type of tile.

Vitreous may be glazed or unglazed. Floor tiles generally consist of vitreous with a porosity of under 3%. Vitreous is manufactured using clays. quartzes and feldspars. The molten feldspars cool to produce the vitreous phase (i.e. the glaze).
Vitreous tiles are substantially more resistant to wear and high levels of mechanical stress.

Porcelain stoneware. a sub-category of unglazed vitreous. possesses a high degree of density and a porosity of under 0.5 %.