a mix of natural clays that, following the drying phase, are fired at more than 1000°C and, depending on the origin of these clays, results in the final product being one particular colour or shade. The manufacturing process can be artisanal or industrial (drawn terracotta). If it is unglazed, it must be treated with impregnating substances after installation. 

it calculates the expansion of tiles if exposed to high temperatures. There are no significant differences between the various types of tiles even if this value can increase in tiles subject to a high vitrification process such as products with a vitrified and compact body.

is the feature by which any material is reversibly altered in size when its temperature changes; more precisely, it expands when the temperature increases and contracts when the temperature falls. According to EN ISO 10545-8 industry standard, thermal expansion is measured with the coefficient of linear thermal expansion as the ratio between the amount that a test sample of the material lengthens when increasing its temperature and the initial length of the same sample.

these are features of resistance to specific temperature (“thermo”) and moisture (“hygro”) conditions, such as LINEAR THERMAL EXPANSION, THERMAL SHOCK RESISTANCE, FROST RESISTANCE, CRAZING RESISTANCE and Coefficient of linear thermal expansion (ISO 10545-8). 

the word “third-firing” derives from the fact that ceramic pieces had already undergone a first firing cycle of the body and a second cycle to fire the layer of glaze. Originally, only decorations in pottery, crockery items and ceramic tiles were earmarked for third-firing.

complementary ceramic elements, characterized by a three-dimensional structure suitable for finishing the special elements of floor and wall coverings (for example steps, junctions, edges, corners, tops and closing elements). 

referred to a surface which is smooth to the touch, as if eroded by the action of water. The tile edges are rounded and uneven, as if worn by the passage of time. Tumbled surfaces are suitable for rustic style areas and renovation works.