Lalique leaves no stone unturned in the manufacture of its crystal. These large crucibles (or pots) are made entirely by hand in the crystal workshop. The master potters can make three fireclay pots, 0.6 to 0.12 metre thick, in 24 days. The crucibles can hold up to 1,000 liters of molten glass. They can only be used after nine to twelve months of drying in a chamber at 140°F (60°C). They must not show any cracks, as they are subjected to very high temperatures when placed in the pot furnace. They have a shelf life of a few weeks, after which they must be replaced.