The inside and outside of the pots are smoothed by hand. No grain must get mixed with the molten material in order to ensure the greatest possible purity of the crystal. Lalique’s potters make all the pots needed to operate the pot furnace. With great care, they shape them, check them during the long drying period (six to nine months) and verify the final result. The pots must not have any cracks. They have a short lifespan (four months at most) due to the extreme temperatures in the furnace. They are therefore replaced regularly with new pots.