pot metal
/ˈpɒt ˌmɛtl/noun
1Any of various alloys of copper and lead (often also containing both zinc and tin).
2Stained glass that has been coloured while molten, so that the colour pervades the whole substance. More fully pot-metal glass.
Origin
Early 17th century; earliest use found in Philemon Holland (1552–1637), translator. From pot + metal.