Slender lead strips used to produce stained glass. There were two distinct cross sections: H and C.
"H" came is used between pieces of glass at the interior of a design, while "C" and "U" came is used around pieces of glass at the design's outer edges. It should be noted that "C" has a rounded exterior, while "U" has a squared exterior. These pieces of came are then soldered together, and often installed in an iron framework to create a window.