Tar was sold in the towns during the Middle Ages. It was needed for making boats watertight and keeping the draught out of the houses. As there was not much wood-land near the towns, tar was usually produced in the vast forests.
People living in the forests earned a great deal of money by producing and selling tar. The income was necessary, since the fields in the forests were small and hard to make a living from. One made tar from tree-stumps, or other pieces of wood which contained a lot of resin. The wood was chopped in small pieces. These were put in a pit in the ground, and covered with peat. Then the wood was set fire to. It was allowed to smoulder for a couple of days, while the tar trickled out of the wood to the bottom of the pit. There, a pipe collected the tar. The tar was then poured into wooden casks, which were sold in town.