Adhesives
Specialised cements are necessary for installation of porcelain tiles, and in the US specifications are set by the Tile Council of America, and supported by the Tile Contractors Association. Porcelain, being denser and heavier than ordinary ceramic tiles, needs a stronger adhesive to hold the weight on walls. Therefore typical ready-mix adhesives are not recommended for porcelain.
Read more about this topic: Porcelain Tile