Whiteness and Gloss Evaluation of Porcelain

Resumo

The influence of the firing conditions on the color characteristics and surface gloss of glazed porcelain after firing in a tunnel furnace is shown for a concrete example. The whiteness of glazed porcelain is determined according to the values of two indices: whiteness WI and tint T_w. It is shown that the whiteness index WI of porcelain is closely associated by an inverse relation with the yellowness b^* CIE L^*a^*b^* and the tinting T_w with the coordinate –a^* (green) right up to inadmissible values. The gloss corresponds to a shiny or highly shiny surface of porcelain glaze.