Sunspots studios has had a working hot shop and has demonstrated glassblowing live for the public since 2001. Today we have two furnaces and 5 glass artists who rotate through our studio 7 days a week.
The newest addition to our studio is our very own Sunspots Signature color glass. Much of small studio glassblowing is done with clear glass. A furnace of melted clear is used to begin every piece and pre-made, melted and re-cooled color is picked up by the molten glass and melted into it during the process. Because one color in this form doesn’t need to occupy a whole furnace, but can rather be stored cold and added, a greater variety of color can be used, and it is more cost effective. However, while the colors are consistent and predictable in this form, variety and experimentation falter. This summer, we got brave and began mixing our colored batches of glass that are anything but predictable.
Our talented “batchers” mix raw ingredients such as silica – a highly purified and consistently sized sand – and soda ash and lime, agents that stabilize the glass and lower its melting point. These three elements are the original glass ingredients, a simple recipe created over 5000 years ago (back when silica was just sand). Nowadays, we know a little more about the chemical process and we’ve found out that trace amounts of additives such as alumina, feldspar and zinc oxide, just to name a few, increase durability and workability, and lower melting points. They measure all of these ingredients carefully and spin them in a mixer, like a mini cement mixer, where it is blended and then melted down in our furnace. They gather it from there, form it, let it cool overnight and it isn’t until the next morning they learn whether everything went just right.
All of this, however, is just clear glass.
In order to make our beautiful new Sunspots Signature colors, small and carefully measured amounts of oxides must go into the mix. Various metals react differently to other chemicals in the batch to form beautiful results…
By adding silver oxide to the mix we get a color we call Silver Opal. Its lush and highly variable color comes from the reaction between the clear glass’ ingredients and the metal oxide. It changes its appearance based on how long and how many times it is heated, how its picked up, and various other factors. All the color and variation you see, however, is just one batch of color.
Adding more oxides to this mix, gets varied results based on how the new metals react with the silver…
Iron Maiden Silver Opal
The iron content of this batch of altered Silver Opal Glass gives it its rich red coloration.
Copper Silver Opal
The beautiful peach and pink colors are created by adding copper into the mixture.
Cobalt Silver Opal
The blue color in this glass owes its beauty from one of the oldest pigments in art, cobalt.