What is Glass Blowing?

Shannon Kietzman

Glass blowing is a process that is used to shape glass. Limestone, sand, potash, and soda ash must first be combined and heated in a furnace at over 2000°F (1093.3°C). While the glass is in a molten state, it is shaped.

Close-up view of potash granules, which are used in glass blowing.
Close-up view of potash granules, which are used in glass blowing.

In order to perform glass blowing, the artist must have a blowpipe. The tip of the blowpipe is preheated by dipping it in the molten glass as it sits in the furnace. A ball of the molten glass is accumulated on the blowpipe and rolled onto a tool called a marver, which is usually a thick sheet of steel that lies flat.

Soda ash, which is used in glass blowing.
Soda ash, which is used in glass blowing.

The marver is important to the glass blowing process, because it creates a cool exterior layer on the glass and makes it possible to shape it. The artist blows air into the blowpipe in order to form a bubble with the molten glass. If the project calls for making a large piece, the artist can create additional bubbles over the original.

Glass is shaped while in a molten state during glass blowing.
Glass is shaped while in a molten state during glass blowing.

With the glass blowing process, a variety of shapes can be created. By using a tool called tweezers, the glass blower can pull the glass or create detail. He or she can also use special paddles made of either graphite or wood to design flat areas in the glass.

Glass blowers use blowpipes to inflate and shape molten glass into items such as vases, bottles or cups.
Glass blowers use blowpipes to inflate and shape molten glass into items such as vases, bottles or cups.

In order to manipulate the glass into various shapes, the glass blower uses tools called jacks. If he or she needs to make cuts in the piece, he or she uses what are called straight shears. Diamond shears, on the other hand, cut off large portions of glass. Once he or she has created a piece of the appropriate size, he or she moves the piece to a tool called a punty. Here, the glass blower can finish the top of the piece.

Glass blowing has a history dating back to approximately 200 BCE. In these early years, the glass shaped was formed around a core made of dung or mud. Typically, the process was used to create containers capable of holding liquids. Today, it is used to create works of art and craft projects. In fact, it is one of the fastest growing hobbies in the United States.

A glass blower may shape molten glass into colorful dishes.
A glass blower may shape molten glass into colorful dishes.

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Discussion Comments


Where can I take a class in glassblowing?


I have a solid glass sphere about 21 inches in circumference, having bubbles inside about the size of my thumbnail, evenly distributed throughout, and coloured inclusions distributed around outer edge of the sphere. Very heavy. Can anyone tell me how this object was made?


Currently using your site to find information for a presentation. Finding everything really easy to understand. Great site! Thanks


can anybody please help me find glassblowing studio's near Chennai, Tamil Nadu, India? I would be very grateful.


I'm from India, Mumbai, and want to know if anyone knows where I could learn glass blowing here. thanks! --ink


i am a glassblower. i want know about glass to metal seal. suresh, india


This really helped me. I'm writing a report on glass blowing. thanks.


The guy up there said silica. I'm only 12 and I'm writing a book right now that involves the main character being a glassblower so I needed to research about it in order to understand the process. When I'm old enough I'll try glassblowing. it seems fun.

I would make my own glass instead of buying it. Handmade work is more efficient.

- Thanks. G.U.S.


What are some of the wages, job availability, or required high school courses for glass blowing?


Can you tell me Study centers for Glass Blowing in India.


can a glass tube inside a larger one be achieved using glass blowing? if yes, how?


Tsk tsk -- a bright 5th grader such as yourself should be able to find this information out on the internets!

I don't work in a glass factory, but I did take a lot of classes in school and set up a workshop in my garage.

As for your questions :

Beach sand is really a combination of lots of things : dirt, silica, shells... So while you could make glass out of beach sand, it wouldn't be very good. If you research ancient glass (which was made thousands of years ago from impure sand) you can see what I mean. It'd be like making cookies using ground up candy instead of sugar -- it would work, but the cookies would taste funny.

The sand used in glass making (silica) is mined and filtered (I'm guessing here, but I don't think it's created so there must be a way to separate the good stuff from everything else) and then sent to glass makers to be combined with the other chemicals and then melted into glass.

Perhaps it'd be childish, but you could write about being a grain of silica and saying goodbye to your friends who are pieces of shells and then meeting new grains made of boron or limestone. Just a thought :)


Where do you get these types of sand? Like you get sand from the beach but were do you get these types of sand?

Thanks. if you could answer this it would be much appreciated.


Hey that helped heaps thanks so much.

Do you work in a glass blowing factory?

And by the way I'm only 11 and I'm doing a big study on Glass blowing at my school and to present my work I'm writing a story as though I'm the piece of sand and that was my experience. So I needed to know what I was going to be combined with.

Many thanks. It help a lot.


From our resident glass blower:

Silica, or "quartz sand" is the sand.

To say that the sand is 'mixed' is a bit of a misnomer -- it's actually melted at very high temperatures. The combination of silica, lime, potash, soda ash, and heavy metal oxides (for color) is heated and mixed in very specific ratios to get different types of glass (such as crystal or 'leaded glass', or Pyrex (borosilicate)).

In other words, it's not something most people do in their garage! Most glass artists purchase their glass pre-made and simply heat it to a working temperature (which is much cooler than the temperature to make it!).

Hope that helps.


What types of sand is used in glass blowing?

And what is the sand mixed with to make the mixture to begin Glass Blowing?


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