Solder is traditionally used to join the lead joints of a stained-glass window.
In a conventional leaded window, individual pieces of colored glass are fitted into H-shaped lead strips called cames. At intersections, the cames are bonded with molten solder, creating a continuous framework that holds the design together. The completed panel is then cemented and supported in its architectural opening.
Solder is usually a metal alloy that melts at a lower temperature than the surrounding lead and glass. A craftsperson heats it with a soldering iron and applies it to the prepared joint. The process requires care because excessive heat can damage glass or distort the soft lead.
This method differs from copper-foil construction, in which foil is wrapped around each glass piece before soldering. Both techniques use solder, but their supporting structures are different.