Heat, Heavy Metal & Murder: The Heart of Glass

Glass is one of those elusive materials that is infinitely curious: to watch glass being made is mesmerizing, and to be honest, a little terrifying. We have 3 glass artists in the shop (ok, 4, but sorry Woody, we're going with the women here): Claire Anderson, Ariel Hill and Minna Koistinen and we asked them everything WE wanted to know about glass. So settle in; it's long, and it's complicated, but you'll learn a lot about this millenniums-old medium.


 Is all glass blown by mouth?

CA: All our glass is blown by mouth. Or, if the pieces are solid, they’re sculpted by hand. Mouth blown glass is a particular niche in the big wide world of glass - the majority of it is factory and machine made.

AH: The short answer is no. Most of my work is blown glass. Some glass is kiln worked and some is shaped from 'solid' glass either by way of a torch or sculpted from hot glass out of a furnace. 

MK: Glass is made in many different ways, and you could say that they’re different professions: flameworking, slumping and fusing, stained glass, glass blowing, glass casting … Each artist focuses on their chosen way of making glass, and becomes an expert in that technique.

Why is handmade glass more expensive than regular glass?

CA: Blown glass is more expensive for many reasons. Firstly because it is made by humans. The set up for a glassblowing studio is very expensive as the furnaces have to run very hot - 1100 degrees celsius sort of hot. Our shop has two furnaces, and three kilns so our energy bills are steep.

AH: Art glass is unique and handmade by a person, not a machine. Also the cost of operating a glass studio to make art pieces is minimum $70 an hour. You are paying for a one-of-a-kind art piece that takes years of practice to achieve and a lifetime of experience to create. 

MK: Factory glass is made by using what we call short glass, which is a glass formula tailored to be used in fast production. It sets quickly and cannot be reheated and shaped again. That means low-cost and machined work with very little human involvement. Studio glass artists operate their facilities themselves. They design and blow the glass, they sell it, take orders from their clients, they are their own packers, shippers, and ultimately run their whole business usually by themselves. 

Are bubbles in the glass a weak point? Why are they formed?

CA: Bubbles are a mark of hand blown glass and are not necessarily bad. It depends on the product and how close to the surface of the glass they are.

AH: Bubbles in glass are formed by air being trapped in the hot glass while it is in the furnace. This sometimes happens when melting new material to fill the furnace with fresh glass. Most bubbles in the glass are not an issue and part of it being handmade.

MK: Bubbles are not a structurally weak point, they are an integral part of mouth blown glass. Sometimes bubbles are added by using salt or baking soda in between layers of glass as a design effect. A bubble in glass is only problematic if it’s too close to the surface and could break.

How long does it generally take to make a piece of glass, like a vase, from beginning to end?

CA: The length of time it takes to create each product just depends on the product and the skill level of the person making it. My husband and I have been blowing glass for 10 and 12 years respectively, so we have become very efficient. Cups we can make in 15-20 minutes, bowls 45 minutes, steins 30 minutes. But that is because we have made thousands of every product and can help each other in the shop. Every piece needs 12 hours to cool in a kiln.

AH: Depending on the colour application or decorative elements of a glass vase it could take anywhere from a 1/2 hour to 3 hours+. Because of the cost of making glass and how physically exhausting it is, artists are always trying to maximize efficiency to create beautiful artworks in a timely manner. 

MK: The first part is getting there, to making a vase that looks like you could sell it. A few years of practice should do it. A vase is a vase is not a vase… The question itself is an anomaly, you cannot generalize. It’s possible to guesstimate how long a particular vase took to make. But all vases are different. Small production vases are made by blowing vases for six hours, and once they cool down, going through a cold working process. Measuring the time that it takes to finish one of those vases would have to be calculated several times by adding up the different work phases.

Is all handmade glass one of a kind?

CA, AH, MK: Yes! Absolutely! All handmade glass is one of a kind. Even in the most consistently created pieces there will be the tiniest differences between each piece.

How do you get the colours in the glass?

CA: Colours are made from heavy metals added to the glass - copper makes blues and greens, manganese makes purples, gold makes pinks, cobalt makes blues, etc. There are very specific 'recipes' for each colour and it is an insanely complex process.

AH: Colours in the glass are added by melting coloured glass that has been prepared by a glass colour factory. It comes in bar form, powder form or as little chunks called 'frit' that can be added to the clear glass. When you see a solid colour in blown glass, this is done by encasing a clear bubble with melted colour bar and then adding more clear glass to sandwich the colour and have it blow out as the chosen colour. 

MK: All glass that is melted in the furnace is clear, and we add colour to it.There are many ways of getting colour into glass, But the most common are either picking up a preheated chunk of colour or rolling clear glass into colour on a steel table (Marver).

How hot does it really get? Are there special safety considerations you have to take in your studios?

CA: Our furnaces run around 1100 degrees celsius, kilns between 500-800 degrees. The ambient temperature in the shop in the summertime can get up to 50 degrees.  We specifically add citrus and sometimes salt to the gallons of water we drink just to keep sugars, energy and electrolytes up. We also just treat it like a kitchen. You never walk behind the person with the glass in hand without announcing you are behind them. You have to focus so hard on the task that communication is key when maneuvering around each other.

AH: When the glass comes out of the furnace it is 1150 degrees celsius, about the heat of molten lava. We use reheating furnaces called 'glory holes' to reheat the glass and keep it malleable. The glass cannot go below 500 degrees celsius or it will break. There are extensive safety precautions that need to be followed. 

MK: I have opted out for a fully electric set up, which is the most comfortable glass studio to work in. We also have air conditioning and a huge exhaust fan up on the roof. Heat is rarely a problem for us. Other safety gear includes Kevlar sleeves to protect your arms and welding glasses for protecting your eyes.

 How do you sandblast glass without breaking it? What effect does it give?

CA: Sandblasting glass is a common practice - we use an aluminum carbonate as our sandblasting medium. It frosts the glass. We also sandblast the interior of our mortar and pestles to add some tooth for a functional effect - better grinding capabilities. It's one of the many 'coldworking' techniques you can do with finished pieces of glass.

AH: Sand etching glass can be done by using various densities of abrasive material. Glass is very strong, stronger than some metals. With my Sediment Series I chose to sand etch the glass to allow a matte finish. This allows the viewer to enjoy the composition of colour without distraction from glare. The tactile element of touching the satin finish is also very enjoyable, and allows the viewer to connect to the material from another sensory experience than sight. 

MK: Sand blasting hits the surface with ground aluminum oxide. You can break the glass if it’s too thin or you hit one spot for too long. A sand blasted surface effect ranges from satiny smooth to a pitted coarse surface depending on how fine or coarse the sandblasting sand is that you are using.

Where do you source your raw product?

CA: We source our clear glass from a company in Germany called 'Crystallica'. Many of our colours are manufactured there as well.

AH: The raw material is ‘nuggets’ of clear glass (not raw minerals or sand). Most glass studios now use Crystalica.

MK: We buy our products from a distributor in Canada.

Do you find there are more women studying the craft?

CA: Yes. There are absolutely more women studying glass these days. It is an ancient practice so women weren't allowed to participate until relatively recently and mostly just in North America. Even from the last generation of glassblowers to now there are more women, but it is still pretty male heavy.

 AH:  Yes, I think for it being a once male dominated art form there are more women choosing to work with glass each year. My graduating class had more females than males. 

MK: Increasingly so. As a historically very male-dominated field, things are changing for the better as more women enter the field. Not for only women, but more diversity is always better.

 How has glassblowing changed over the centuries?

CA: Humans have been working with glass since the Egyptian times. Blowing, in essentially the form that we see today started with the Romans. Probably the peak of craftsmanship happened when the Italians had a worldwide monopoly on blown glass - they kept all of their glassblowers and studios on the island of Murano and closely guarded their secrets (they would murder glassblowers or their families if they left the island). Nowadays we finally have a more scientific understanding of what glass is and while many of the tools and processes are similar to what they were then, we can more easily create optically clear glass. We live in the age of glass now. With lenses we can see the universe as well as the microverse, with fibre optics we can communicate globally, we microchips 'grown' from silica we can endlessly store data, with tempered glass we have changed architecture. Glass is an amazing material and its history and contemporary understanding is so complex. 

AH: As with any art form, the collective knowledge of the craft grows with time. Also technology has played a huge role in its advancement. The process has not changed dramatically, the tools have improved and evolved but they are still based from what has been used for centuries. I would say the access to information is the biggest development, along with certain equipment advancements. 

MK: Same answer (women now do it). However, the techniques have not changed in the last 5000 years and we still use the same tools. The biggest change has been technology. Whereas using natural gas as fuel for a glass studio used to be the norm, other ways off powering up your equipment are being worked on. Electricity is used effectively with highly efficient control panels boosting the signal and saving electricity. Wind and solar power are already being used in parts of the world where it’s possible. A portable furnace that works on cooking oil is close to coming to the market.

 How long do you study or apprentice the craft?

CA: Nowadays in North America, and some European countries, schooling is how you start with glass. However, it is a craft that takes a ton of time and practice. And regular practice. So to stay in it and keep your 'hands hot' you need to stay in studios creating product, and every person has a different way of doing this. It takes 30 years of REGULAR working with the material to be considered a master, but it is a material with non-stop learning and improving. If you are a true glass artist, you spend your life studying the craft.

AH: A lifetime. I graduated with my B.F.A from the Alberta University of the Arts with a major in glass. However, that is still very 'green' in terms of experience in the glass world. I am now 6 years in and still learning. I would say it takes at least a decade to become proficient with the material. In the first couple years you are just trying to understand the material, the heating and cooling and managing the mechanics.  Like a baby deer on ice, except you're on fire and have sweat in your eyes. 

MK: Due to the prohibitive cost of the artform, finding apprenticeships is near impossible these days. Most people go through a 3 to 4 year program in a college or university. I went through a six year program in a Finnish university and graduated with a Masters degree.


Have a burning need to know something about a particular fine craft medium or art form? Let me know in the comments. We'll get you your answers, no worries.

photo: glassworks by (L to R): Claire Anderson, Minna Koistinen and Ariel Hill.

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