Briquetage or very coarse pottery (VCP) is a coarse ceramic material used to make evaporation vessels and supporting pillars used in extracting salt from brine or seawater. Thick-walled saltpans were filled with saltwater and heated from below until the water had boiled away and salt was left behind. Often, the bulk of the water would be allowed to evaporate in salterns before the concentrated brine was transferred to a smaller briquetage vessel for final reduction. Once only salt was left, the briquetage vessels would have to be broken to remove the valuable commodity for trade.