text: The principal methods of this are enamelled glass, essentially a technique for painting patterns or images, used for both glass vessels and on stained glass, and glass paint, typically in black, and silver stain, giving yellows to oranges on stained glass.  All of these are fired in a kiln or furnace to fix them, and can be extremely durable when properly applied.  This is not true of "cold-painted" glass, using oil paint or other mixtures, which rarely last more than a few centuries.