CCG (as it'
s known) is made by small pieces of metal (usually silver and/or gold) that are held in the flame of the torch until vaporized (often called 'fuming'). The
glass is rotated in this vapor stream until a fine layer of the vaporized metal is visible on the surface of the
glass.
After this, clear
glass is applied (often in 'dots' and 'lines') to 'encase' the vaporized metal in between layers of
glass. There are many techniques and methods of applying the fumes and clear
glass making a myriad of different colors, and endless types of patterns that one can come up with. The colors produced with fumed metals are best when they are translucent, vibrant, and reflective. As the pipe darkens with use, the colors (many barely visible) become darker and much more conspicuous, thus causing the appearance of much richer 'color change' (the
glass itself doesn't actually change colors though).
Color changing
glass is used in a variety of products such as glass vases,
oil lamp bases, perfume bottles, containers, smoking accessories, and so forth.