Page 103 - Vitromex USA Catalogue

Do you know the difference between porcelain & ceramic tiles?
The manufacturing of ceramic and porcelain tiles follows the same fundamental methodology that has been used for thousands of years: that is, shaping clay and cooking it at very high temperatures to remove water and harden it. Modern manufacturing is fundamentally, a refinement of this ancient process.
The main difference between ceramic and porcelain tiles start from the different clays and raw materials, firing temperatures and periods used. Porcelain tiles are generally made of thinner and denser clay than ceramic tiles and are pressed and cooked for longer and at higher temperatures. This results in a product that is considerably harder and more impermeable than ceramic. In fact, to be considered a porcelain tile is the lower water absorption rate (<0.5%). Porcelain can be used with caution in wet areas and in particular outdoors (in covered, debris free areas) where it is less prone to the cracks when is exposed to humidity and the freeze-thaw cycle.
In summary, both glazed porcelain and ceramic tiles can look the same, be impermeable on the surface but withstand different minimum breaking strength.