These are some pictures I took when I toured a pewter factory in Malaysia.
The permanent mold casting process uses molds, often made from metal, which are used over and over, as opposed to other techniques like sand casting, lost foam or investment casting where the molds are destroyed to remove the casting. The molds in this picture are for a handle on a mug, there are pins in the mating faces of the molds to align the halves correctly and steps cut in the top corners of the molds so the halves can be levered appart when it's time to remove the casting. When the molten pewter is poured from the ladel into the molds, the molds are clamped together and tilted up on an angle to reduce the likelyhood of an air lock in the casting, as the molds start to fill the angle is steadily reduced to horizontal. Pewter has a very low melting point and solidifies extreamly quickly.