71 Glass Blowing Facts For Kids To Understand This Complex Process

Anusuya Mukherjee
Oct 25, 2023 By Anusuya Mukherjee
Originally Published on Jan 13, 2022
The fumes during Glass Blowing can cause different diseases.
Age: 3-18
Read time: 5.3 Min

Glass objects are made by blowing glass into various shapes and sizes.

It is an age-old practice, and molten glass is used to perform this task. The blown glass can be molded into the shape and size of your own choice.

This technique has been used since the 1st century BC. Glass-blowing involves the inflation of molten glass into the shape of a glass blob (a process called mold blowing) using a blow tube, which is then molded into the desired shape.

The basic process of glass making proceeds in the following manner:

Raw materials like sand and limestone are heated in a special furnace. At that temperature, it assumes a liquid-like consistency.

While the mixture is still soft, metals and other compounds are added to make the colored or textured products. Workers then shape and mold the mixture into a vessel of their own choice. When the glass cools down to a lower temperature, it hardens in its new shape.

Keep on reading to learn more about this interesting process. You can read more facts about glass and facts about sunglasses!

Facts About Glass Blowing

Here are some interesting facts about this art form that you might not have heard of before.

Starting from the middle ages, this practice has gained recognition worldwide. However, modern glass-blowing came with an increased risk of lung, stomach, colon, and bladder cancer. Glass shops use metallic compounds and other raw materials, responsible for cancer risks among the employees.

In a study conducted in glass manufacture plants based in Italy, Finland, and Sweden, it was seen that the workers showed significantly increased risks for lung cancer. In another population-based control study conducted in China, female workers who worked in glass factories exhibited an increased risk of lung cancer than male workers employed in glass and ceramics production factories.

Another disease has been widespread among glass workers called Metal Fume Fever. This occurs when workers inhale the fumes generated during the melting of the glass. The symptoms of this disease include metallic taste in the mouth, shortness of breath, gastric pain, and flu-like symptoms. Constant exposure may also lead to kidney dysfunction.

Glass blowing comes with added dangers of burns, cuts, toxic fumes, eye damage, cancer, and chronic pain. Workers should be given proper access to safety gear like aprons and gloves. Supervising them to see if they are following proper safety protocols will lower the chances of injury.

When compounds like carbon, nickel, and sulfur are added to molten glass, it results in a glass called brown glass. This brown color will protect the contents of the glass vessel from direct exposure to sunlight and, in turn, helps preserve the flavor and freshness. Brown glass is thus mainly used for food and drink preservation.

Colored glass is made by adding powdered metals or oxides of metal to molten glass. Window glass is often made with such colored glass in the glass shop. The blown glass assumes color depending on the type of metal used.

Fine glassware can be made by adding cobalt (to form a cobalt blue color) or copper (to create a bluish-green color). Amber glass can be made by adding iron, sulfur, and carbon.

This mixture gives it a rich amber hue which will remind you of dark coffee. The color becomes appealing to the eyes and is used to store food and drinks.

The Glass Blowing Process

This technique requires two kinds of raw materials; different types of sands and glass remains. These materials are mixed together and melted at 1500 degrees Celsius in a furnace to form a molten solid- a form intermediate between solid and liquid.

The raw materials include hot glass is melted to form molten glass. Then that soft glass is gathered at one end of a blow tube and blown into a molten glass blob.

The molten portion is then rolled over a metal carved mold or stone of the desired shape to give it a final shape. Next, the stems, feet, or handle are added by welding the soft glass.

At that point, it can also be modified by cutting or shaping with the help of hand tools. The two major methods of glass-blowing are free-blowing and mold-blowing.

Glass Blowing is one of the oldest techniques that is in practice even today.

Different Glass Blowing Techniques

This art form has a large number of techniques. These include core forming, casting, blowing, mold-blowing, pattern-molding, trailing, cutting, fire-polishing, marvering, pontil, kick, and weathering.

Let us talk about each one of them in detail:

Core forming: The earliest technique of glass making

Casting: You can mold the glass into either a closed mold or an open former by this technique.

Blowing: Molten glass is used to form a hollow blob and then spread on a mold

Mold Blowing: Using a pre-made clay, metal, or wooden mold, the person who blows glass can shape it.

Pattern-molding: After partially forming on a mold, the glass is then expanded and twisted to create the desired pattern

Trailing: exciting designs can be created by using glass threads

Cutting: It is mainly used in cold glass items, and the people who do this are called glass-cutters.

Fire polishing: the method in which the molded glass vessel is reintroduced into the furnace to smooth out any imperfections.

Marvering: The glass is rolled over a flat surface to form patterns and remove irregularities.

Pontil: A pontil is a metal rod that helps the glass-maker hold and work with the glass at high temperatures. While holding onto a pontil, he attaches decorative items or handles to the structure. The pontil often leaves a mark at the point where it was attached to the glass.

Kick: With the help of a pontil, a depression is made at the vessel's bottom.

Weathering: Over millions of years, glass in ancient monuments assumes characteristic hues resulting from weathering.

Glass Blowing: History

Artisans from ancient Syria first implemented glass-blowing techniques.

The blown glass was exported all across Rome as luxury items. This was when blowing glass was considered an art form. Later, glass making was extended to a more common spherical shape. 

Here at Kidadl, we have carefully created many interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for 71 glass blowing facts for kids to understand this difficult process, then why not take a look at how is sea glass made or dryer fire facts?

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Written by Anusuya Mukherjee

Bachelor of Arts and Law specializing in Political Science and Intellectual Property Rights

Anusuya Mukherjee picture

Anusuya MukherjeeBachelor of Arts and Law specializing in Political Science and Intellectual Property Rights

With a wealth of international experience spanning Europe, Africa, North America, and the Middle East, Anusuya brings a unique perspective to her work as a Content Assistant and Content Updating Coordinator. She holds a law degree from India and has practiced law in India and Kuwait. Anusuya is a fan of rap music and enjoys a good cup of coffee in her free time. Currently, she is working on her novel, "Mr. Ivory Merchant".

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