It wasn’t until the 80’s when the so-called Godfather of artistic glass blowing Bob Snodgrass accidentally discovered that coating a pipe or bong with silver or gold fumes would cause it to gradually change colours. He vaporized a metal alloy to create a fume wherein the glass is rotated, until a visible layer of vaporized metal is attached to the surface of the glass. After this, another layer of glass is added to encase the metal between these two layers. The pipe appears to change colors because the metal alloy inside of it contains very lightly coloured ions. Over time, resin builds up behind the thin layer of ions, creating a dark background which, in contrast, makes the ions’ colours much more visible. Once the pipe is cleaned, the ions become nearly invisible again and you can begin the colour changing journey all over again!