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.
