How is Iridescent Glass Made?
Here's another one of those sciency posts…
Iridescence is one of my favorite features available in sheet glass. Not only can you make the most magnificent dragon wings, but you can also alternate colors (see picture below) and position of patterning to capture variations of color of the iridescent layer.
So, how is it made? Well, you must remove the salt from the glass with an acidic water solution to create a separate layer that breaks apart into a prism upon cooling. The resulting layer reflects light differently than the underlayer.
– (Blank stares) –
OR! You can do it with chemical reactions.
– (Ahhhhs and nods) –
You can create an iridescent layer on glass by annealing it, which makes it hot but not melty. Then you push it into a reduction chamber with a combination of acid vapor, metal oxides, and salt during a process called "fuming."
– (Perplexed expressions) –
Oh, look… a handy video from the Corning Museum of Glass demonstrating iridizing a sheet of glass out of a blown bubble.
Stay Glassy,
Leia Powell
Master Stained Glass Artisan
Wildcat Mountain Artistry