Characteristics of pores responsible for staining of polished porcelain tile

The susceptibility to staining of polished porcelain tile has been investigated by various authors for over a decade. However, the literature offers little information about the characteristics the finished product should present in terms of final porosity in order to prevent staining. This paper discusses the results of a comparative analysis of the final porosity of two types of commercial unglazed polished products showing dissimilar staining behaviors. The approach to this theme differs from that of other works reported in the literature in that it clearly identifies the main types of pores responsible for staining under the conditions evaluated here.