How do you colour the glass in glassblowing?
It's a question we're asked at least once a day in our glassblowing gallery — how do we colour the glass?
We don't just paint or stain glass pieces that we buy (that's a common question, too). We actually make all of our pieces from molten glass in our very own hot shop, and we add the colour while we're making the pieces.
But how do we do that?
All of our glass pieces start out by gathering clear molten glass from our furnace.
Before gathering the glass the glassblower will spread really small pieces of coloured glass called "frit" on the marver (a flat steel tabletop).
They'll then roll the gather of clear molten glass overtop of the frit to add colour to the gather. The clear glass is so hot that the frit sticks and melts into it!
The final product will then have streaks or speckles of colour in it, depending on how they work, twist, or roll the glass after the frit was been collected.
Less frequently we'll use colour bar to colour our pieces.
Colour bar is a rod of coloured glass that is used to add an even layer of colour to a piece, as opposed to the more speckled or streaked finish created by using frit.
The colour bar is first warmed in the annealer. The glass blower then collects a small gather of clear molten glass on a pipe and uses the gather to pick up the hot piece of colour bar.
From there the colour bar is heated it in the glory hole until it becomes so hot that the glassblower can blow a small bubble in it. They'll then often coat the bubble in clear glass and continue to blow and form the item they're creating. The result is a piece with consistent colour throughout.
Minerals and Elements
Now you're probably thinking, "that's great, but how do they get the colour in the frit and colour bar?"
The answer is minerals and elements. Different colours of glass are created by adding different minerals and elements to clear molten glass.
For example, cobalt is added to clear glass to create a rich blue colour, and gold salts are added to glass to create cranberry pink.
See it for yourself!
Want to see how the colour is added? Watch this video!
So there you have it! The next time you stop by our gallery, maybe you'll be the one to answer the ever common question "how do you get the colour in the glass?"
Looking for a beautiful piece of blown glass for your own collection? We may have just the thing, or we might be able to make it for you! Explore our online shop or email us at firstname.lastname@example.org.