5. First firing (biscuit firing):
The dry pieces are subjected to a first firing at a temperature of 850°C. This step, known as 'biscuit firing', strengthens the pieces and makes them more resistant. The pieces acquire a grey texture at this point.
6. Second firing (Vitrification):
After bisque firing, the pieces are covered with ceramic glaze. The glaze not only improves the appearance but also provides an additional protective layer. The pieces are fired again, this time at a temperature of 1250°C, which causes the glaze to vitrify and changes the colour of the pieces according to their composition. The result is a durable, resistant Vulcano Gres ceramic with a wide range of colours available.